 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued March 7, 2017                 Decided July 18, 2017

                       No. 16–1191

    BELLAGIO, LLC, D/B/A BELLAGIO LAS VEGAS, ET AL.,
                      PETITIONERS

                            v.

           NATIONAL LABOR RELATIONS BOARD,
                     RESPONDENT


       Consolidated with 16-1192, 16-1256, 16-1258


      On Petitions for Review and Cross-Applications
                for Enforcement of Orders of
           the National Labor Relations Board


   Paul T. Trimmer argued the cause for the petitioners.
Gary C. Moss was with him on the briefs.

    David Casserly, Attorney, National Labor Relations
Board, argued the cause for the respondent. Richard F.
Griffin, Jr., General Counsel, Jennifer Abruzzo, Deputy
General Counsel, John H. Ferguson, Associate General
Counsel, Linda Dreeben, Deputy Associate General Counsel,
Usha Dheenan, Supervisory Attorney, and Marni Von Wilpert,
Attorney, were with him on the brief.
                              2
    Before: HENDERSON and SRINIVASAN, Circuit Judges, and
GINSBURG, Senior Circuit Judge.

    Opinion for the Court filed by Circuit Judge HENDERSON.

    Opinion concurring in part and dissenting in part filed by
Circuit Judge SRINIVASAN.

    KAREN LECRAFT HENDERSON, Circuit Judge:

       “In Vegas, everybody’s gotta watch everybody
       else. Since the players are looking to beat the
       casino, the dealers are watching the players.
       The boxmen are watching the dealers. The
       floormen are watching the boxmen. The pit
       bosses are watching the floormen. The shift
       bosses are watching the pit bosses. The casino
       manager is watching the shift bosses. I’m
       watching the casino manager. And the eye in
       the sky is watching us all.”

—Sam “Ace” Rothstein, CASINO (Universal Pictures 1995).

     Because they are luxury casino resorts, petitioners
Bellagio and The Mirage (collectively, casinos) have
extraordinary security needs. Each has a high-end jeweler.
Bellagio boasts an art gallery that has displayed Fabergé eggs
and the works of Picasso. Both casinos house an array of slot
machines, gaming tables, count rooms and cages containing
vast amounts of cash and cash-equivalent gaming chips. To
protect all of that valuable property—not to mention the
property and physical safety of guests who hope to win big or
have a good time trying—each of the casinos relies on a
sophisticated network of surveillance cameras, locks, alarms
and computers. The equipment is essential for deterring,
detecting and recording wrongdoing, including misdeeds at the
                                   3
hands of the casinos’ own employees. And when those
employees are suspected of wrongdoing, the casinos use
hidden cameras to conduct targeted investigations.

     We must decide whether the surveillance technicians
(techs) who control the casinos’ surveillance, access and alarm
systems and help to investigate errant employees are “guards”
under section 9(b)(3) of the National Labor Relations Act
(Act), 29 U.S.C. § 159(b)(3). Designed to avert employee
conflicts of interest, section 9(b)(3) precludes the National
Labor Relations Board (Board) from certifying a union to
represent “guards” who “enforce,” against colleagues and other
persons, “rules to protect property of the employer or to protect
the safety of persons on the employer’s premises[.]” Id. The
Board’s Regional Director found that the techs do not enforce
such rules and so are not guards. Thereafter, the Board
certified the International Union of Operating Engineers Local
501 (Union)—which represents several non-guard employees
of the casinos—as the exclusive collective-bargaining
representative for a unit of techs at each casino. The casinos
refused to bargain with the Union. The Board concluded that
the casinos thereby violated section 8(a)(1) and (5) of the Act,
29 U.S.C. § 158(a)(1), (5). 1 In two materially identical

     1
         Section 8(a)(1) makes it “an unfair labor practice for an
employer . . . to interfere with, restrain, or coerce employees in the
exercise of the rights guaranteed in” section 7, including the right “to
bargain collectively through representatives of their own
choosing[.]” 29 U.S.C. §§ 157, 158(a)(1). Section 8(a)(5) makes
it “an unfair labor practice for an employer . . . to refuse to bargain
collectively with the representatives of his employees[.]” Id.
§ 158(a)(5). “Because of the overlap in provisions, an employer
who violates section 8(a)(5) also, derivatively, violates section
8(a)(1).” Scomas of Sausalito, LLC v. NLRB, 849 F.3d 1147, 1153
n.3 (D.C. Cir. 2017) (internal quotation omitted).
                                4
decisions, it ordered each casino to recognize and bargain with
the Union.

     The casinos petition for review of the Board’s orders.
The Board seeks enforcement. We grant the casinos’
petitions, deny the Board’s cross-applications for enforcement
and vacate the Board’s decisions and orders, which are contrary
to the record evidence considered as a whole. 29 U.S.C.
§ 160(e), (f). On our view of the record, the techs’ day-to-day
duties—sensitive ones peculiar to the modern gaming
industry—call for them to enforce against coworkers and
others the rules that protect the casinos’ property and guests.
Accordingly, under section 9(b)(3), the techs are guards who
can be represented only by an all-guard union.

                     I. BACKGROUND

     Guard status is a “factual question[]” tied to the particulars
of each case. Burns Int’l Sec. Servs., 278 NLRB 565, 569
(1986). Whether specific employees are guards “can be
answered only by carefully examining their duties.” Id. We
therefore discuss the techs’ duties in detail, drawing our
descriptions from the testimony that casino personnel gave
during representation hearings conducted by a Board hearing
officer. We then summarize the Board proceedings.

            A. THE TECHS’ DUTIES IN CONTEXT

     MGM Resorts International owns and operates several
casino resorts in Las Vegas, Nevada, including petitioners
Bellagio and The Mirage. For the most part we do not
differentiate between the two casinos because their practices,
as relevant to this case, are all but identical.
                                5
                1. Surveillance and security

     Each of the two casinos has a surveillance department and
a security department. As required by Nevada law—which
provides that a licensed casino must have a “surveillance
system . . . to assist the licensee and the state in safeguarding
the licensee’s assets [and] in deterring, detecting and
prosecuting criminal acts,” NEV. GAMING REG. 5.160(2)—each
casino’s surveillance department uses a network of high-tech
cameras to oversee slot machines, gaming tables, count rooms
and cashier cages. The cameras transmit live footage to a
monitor room, where two to four surveillance operators per
shift watch the footage in real time for suspicious activity, and
to a server room, where the footage is stored on a “really fancy”
“s[o]uped-up” computer system for future use. Mirage Tr. 54.
Stored footage is critical because hundreds of cameras (about
1,100 at Bellagio and 700 at The Mirage) canvass the gaming
floor; the few on-duty operators cannot see everything as it
happens.

     Ultimately, the surveillance department’s job is to protect
the casino’s property and guests “according to policy and
procedure,” especially by ensuring that dealers and players do
not cheat the games. Mirage Tr. 32. The security department
has the same job but with an additional focus on non-gaming
areas such as the jewelers and art gallery, retail and recreational
areas, hotel towers, parking garages and employee-only
locations. In other words, security officers patrol the entire
resort for potential threats to the “security of the guests, the
employees and the property itself.” Id. at 172. A second
camera system, not subject to gaming regulations, covers the
non-gaming areas. The security officers monitor non-gaming
video feeds in their own monitor room. The officers on patrol
respond to reports from that room and from the surveillance
department’s monitor room. In the event of cheating or a
                                 6
safety threat, the officers take appropriate action such as
restraining a patron or escorting him off the property.

                          2. The techs

     The techs work with both the surveillance and security
departments and have wide-ranging duties. They are charged
with designing, installing and maintaining the surveillance
department’s gaming-floor camera system in a manner that
complies with Nevada gaming regulations. Maintenance does
not mean merely fixing broken equipment. The gaming-floor
setup is often in flux. On the frequent occasions when slot
machines and table games are moved, the techs must adjust the
camera coverage so that it still captures all of the legally
required information, including the identity of dealers and
players, card ranks and suits, bets, payouts and the like. By
law, the coverage must be adequate to prevent cheating. Thus,
the techs are in frequent and direct contact with both the
surveillance monitor room and Nevada’s Gaming Control
Board, proposing coverage, taking pictures, making
submissions on deadline and obtaining the necessary
regulatory approvals.2



    2
        As an example, Bellagio techs in 2015 designed and installed
ad hoc surveillance coverage for a Super Bowl party involving an
auxiliary sports book and gaming pit. One of the techs was in direct
communication with the Gaming Control Board, forwarded a
proposed layout and obtained the necessary regulatory approval.
That was consistent with standard practice: about once a month on
average the techs must configure and get regulatory approval for
coverage of a special gaming event. See, e.g., Mirage Tr. 66-68
(auxiliary betting stations for fight between Floyd Mayweather and
Manny Pacquiao); Bellagio Tr. 75-83 ($500,000 baccarat
tournament).
                                 7
     The techs also oversee the server room and are solely
responsible for the elaborate computer system that manages
“[b]asically every aspect of . . . digital surveillance,” including
not only the surveillance department’s cameras but the security
department’s as well. Bellagio Tr. 58. No one except the
techs and the surveillance director work on that computer
system or on the cameras and related equipment maintained
throughout the casino. And because the techs and the
surveillance director are “the keepers of the system,” id. at 101,
only they can unilaterally turn video feeds on and off; add and
delete cameras and users; restrict a user’s access to particular
views and footage; stop cameras from recording; and delete
footage from the server. The surveillance operators and
security officers have no such authority. In practical terms,
then, a tech can significantly affect what an operator or officer
sees on video at any given moment.

     The surveillance operators and security officers rely on
and communicate daily with the techs. The operators and
officers report any problem with coverage or equipment so that
the techs can correct it. The techs train the operators and
officers on how to use the computers, change camera views and
archive video files. The techs also help the operators and
officers extract footage from the server for evidentiary use.
And if tampering with a camera is suspected, the techs, not the
operators or officers, are the ones who investigate.3




    3
        Surveillance operators and security officers are on-site 24
hours a day, whereas the techs’ on-site hours run between about 3:00
a.m. and 2:00 p.m., when their work on the gaming floor is least
likely to interfere with business. But because the surveillance
system is “vital” to operations, Bellagio Tr. 122, because
malfunctions can “jeopardize” the casinos’ gaming licenses, id. at
                                 8
     Moreover, the techs’ duties reach well beyond everyday
camera coverage. The techs maintain each casino’s electronic
access system. The access system consists of code-activated
magnetic locks that control access to “sensitive area[s]” like the
server room, the monitor rooms, the art gallery, executive
offices, count rooms and the main casino cage — the last of
which is subject to especially restrictive controls because it is
“the hub of all gaming funds” and is much “like [a] bank” in
the amount of money it houses. Mirage Tr. 58; Bellagio Tr.
89, 93. Only the techs and the surveillance director have
electronic control over the access system. Accordingly, and
although they act at the direction of human resources and other
supervisory personnel, only the techs and the surveillance
director can program the codes that limit each employee’s
access to specific locations within the casino. The techs
themselves have full access to all areas because they must tend
to cameras and equipment “almost everywhere.” Bellagio Tr.
145.

    As with the access system, the techs install and maintain
computerized alarm systems for jewelry, art displays, count
rooms and cages. No other employees do such work. The
techs have the ability to arm and disarm the alarms. And if a
miscreant defeats an alarm, the techs investigate how he did so.

    Finally, and perhaps most importantly for our purpose,
techs often participate in targeted investigations of fellow
employees suspected of wrongdoing.           In the typical
investigation—known as an “integrity check,” a “special
operation[]” or simply a “special[],” Bellagio Tr. 105, 177,
183—the tech either installs a purpose-built covert camera
somewhere in the target employee’s work area or “lock[s]” an

38, and because no one else can perform the techs’ work, at least one
tech remains on call at all times.
                                 9
existing camera onto the area without the employee’s
knowledge. 4 Mirage Tr. 110-11. Special operations are
conducted, on average, about once or twice per month.
Because the tech has to devise coverage that will capture the
suspected misconduct, he is usually given “[s]pecifics” like the
“nature” of the misconduct and “what kind of employee” is
suspected of it. Id. at 105-06; see id. at 164, 190, 195 (tech
typically knows why he is setting up coverage in specific area);
but see id. at 106 (tech typically is not given target employee’s
name).

     Although a tech’s role in a special operation is limited to
ensuring proper coverage and retrieving footage afterward, his
participation is essential: no other employees devise and install
secret cameras. Also, the surveillance and security personnel
conducting the investigation count on the tech to coordinate
with them, especially to maintain secrecy. Just as “what
happens in Vegas stays in Vegas,” see History of Las Vegas,
LAS VEGAS CONVENTION AND VISITORS AUTHORITY,
www.lvcva.com/stats-and-facts/history-of-las-vegas/ (noting
tagline coined in 2003), the casinos have a “policy” that
“whatever happens in surveillance doesn’t leave,” Bellagio Tr.
139-40. During a special operation, a tech is not to disclose
its existence to personnel who do not need to know about it.

    4
         Again as an example, The Mirage’s techs in 2015 hid a
camera inside a clock radio within a staged guest room to catch a
housekeeper stealing items planted in the room. That was consistent
with standard practice. See, e.g., Mirage Tr. 92-94 (techs installed
covert camera in air duct to investigate graveyard-shift supervisor
suspected of sleeping on job); id. at 196-98 (techs installed covert
camera in ceiling to investigate security employee suspected of
stealing lost-and-found items); Bellagio Tr. 179-81 (techs installed
covert camera in ceiling to investigate poker dealer suspected of
stealing from coworkers).
                                10
Indeed, to ensure that the operation is not compromised, the
tech must sometimes use his control over the computer system
to “cut off” video coverage to some employees and tell them a
“story” that the system is malfunctioning. Id. at 175-76.

     The foregoing duties are sensitive and important enough
that the techs are considered “key employees” under Nevada’s
gaming regulations. Mirage Tr. 50-51. A key employee is
one who has “the power to exercise a significant influence over
decisions concerning any part of the operation of a gaming
licensee . . . .” NEV. GAMING REG. 3.110(1). Casinos subject
key employees to special restrictions and background checks.
And so it is with the techs.                Because of the techs’
comprehensive knowledge and access, the casinos must put
“quite a bit of trust . . . in [their] integrity.” Bellagio Tr. 138.
The techs are therefore subject to more stringent background
checks than are most other employees, including security
officers.

     Having detailed what the techs do, we complete the picture
by describing what they do not do. Unlike a security officer,
a tech does not carry a weapon or handcuffs; does not patrol
the resort for misconduct; does not restrain an unruly guest; and
does not physically confront a cheater or a thief. Unlike an
officer or surveillance operator, a tech does not watch live
feeds or stored footage for wrongdoing and does not document
it.5 And when a tech participates in a special operation, he
does not confront or interview the targeted employee.




    5
        Like all other employees, however, a tech is expected to
report suspicious activity when he encounters it.
                                11
                B. THE BOARD PROCEEDINGS

     The Union petitioned the Board for certification under
section 9(c) of the Act, 29 U.S.C. § 159(c), seeking to represent
a bargaining unit of all the techs at each of the two casinos.
On each of its two petitions, the Union did not fill out Box 7,
which asked whether it had requested recognition from the
respective casino and what the result was. The casinos moved
to dismiss the petitions, relying on 29 C.F.R. § 102.61(a). In
pertinent part, section 102.61(a) provides that “[a] petition for
certification . . . shall contain . . . [a] statement that the
employer declines to recognize the petitioner as the
representative” of the bargaining unit the petitioner claims is
appropriate. Id. § 102.61(a)(8). The Board’s Regional
Director denied the casinos’ motions, rejecting their argument
that section 102.61(a) required dismissal.

     The casinos then opposed the petitions on the merits. As
relevant here, they argued that the techs are guards under
section 9(b)(3) of the Act, precluding the Board from certifying
the Union as the techs’ representative because the Union
represents non-guard employees.6

    A hearing officer conducted hearings on both of the
Union’s petitions. At the outset, the Union asked the casinos
for recognition. The casinos declined. Casino personnel
then testified to the techs’ duties as described above.



    6
        The casinos also argued that the techs are “confidential
employees.” See NLRB v. Hendricks Cty. Rural Elec. Membership
Corp., 454 U.S. 170 (1981). They renew that contention here but
we do not consider it in light of our conclusion that the techs are
guards.
                               12
     After reviewing the testimony, the Regional Director
concluded that the techs are not guards, reasoning that their
“responsibilities are limited to the installation, modification,
removal, and maintenance of the video monitoring system.”
Joint Appendix (JA) 438, 881. In the Regional Director’s
view, the techs do not “enforce rules to protect property or
persons” because they “make no rounds, and are required to
watch for nothing other than issues affecting the surveillance
system.” JA 438-39, 881. The Regional Director noted the
techs’ role in special investigations and their control over other
employees’ access to the surveillance system and to sensitive
areas within the casino. But he gave no weight to those facts
and stated that installing cameras “to assist others” in enforcing
rules is “insufficient” for guard status. JA 439, 881.

     The Regional Director found Bellagio’s techs to be one
appropriate bargaining unit and The Mirage’s techs to be
another. He ordered that a representation election be
conducted for each unit. In each case, the techs voted for the
Union, which was thereafter certified as the exclusive
collective-bargaining representative for each unit.         The
casinos sought review before the Board, which denied it on the
ground that the casinos had “raise[d] no substantial issues.”
JA 443, 885. In a footnote, the Board “agree[d]” with the
Regional Director’s analysis of the guard issue. JA 443 n.1,
885 n.1. It added that “the Board and the courts have long
rejected the notion that individuals should be deemed guards
because their installation or maintenance of equipment is an
integral part of a larger security system that other individuals
actually operate.” Id. (citing Wells Fargo Alarm Servs. v.
NLRB, 533 F.2d 121, 124 (3d Cir. 1976); Am. Dist. Tel. Co.,
160 NLRB 1130, 1138 (1966)).

    The casinos could not seek judicial review at that point,
see Magnesium Casting Co. v. NLRB, 401 U.S. 137, 139
                               13
(1971), so they refused to bargain with the Union and renewed
their claims in defense against the Union’s unfair labor practice
claims. In May 2016, the Board issued two materially
identical decisions concluding that each casino violated section
8(a)(1) and (5) of the Act by refusing to bargain. In each
instance, it ordered the respective casino to recognize and
bargain with the Union.

                       II. ANALYSIS

    The casinos now seek review in this Court, urging that (1)
the Union’s petitions should have been dismissed for failure to
comply with 29 C.F.R. § 102.61(a); and (2) the techs are guards
under section 9(b)(3) of the Act. We reject the first claim but
agree with the second.

        A. THE CASINOS’ PROCEDURAL OBJECTION

     The casinos’ objection under section 102.61(a) need not
detain us long. As noted, the provision states in relevant part
that “[a] petition for certification . . . shall contain . . . [a]
statement that the employer declines to recognize the petitioner
as the representative” of the bargaining unit the petitioner
claims is appropriate. 29 C.F.R. § 102.61(a)(8). The casinos
argue that “shall” means compliance is mandatory. That may
well be so. See Alabama v. Bozeman, 533 U.S. 146, 153
(2001) (“The word ‘shall’ is ordinarily the language of
command.” (some internal quotations omitted)). And there is
no disputing that the Union’s certification petitions fell short.
Box 7 of the standard-form petition asks whether and when the
petitioner requested recognition and if the employer declined
or simply did not respond. Here, the Union left Box 7 blank.

    But the casinos cite no authority for the proposition that
dismissal is always the remedy for a non-compliant petition.
They contend that “[p]rocedural due process requires the
                                14
[Board] to adhere to its own rules.” Br. of Pet’rs 41.
Assuming arguendo they are correct, the assertion gets them
nowhere; the text of section 102.61(a) does not dictate
dismissal for a violation, let alone a de minimis violation cured
at the representation hearing.7 That is what happened at the
hearings here: the Union sought recognition and the casinos
declined. The casinos do not contest that the violation was
thereby cured. Indeed, they conceded at oral argument that
they suffered no prejudice. Oral Arg. Recording 2:00-2:26,
5:55-5:57.

     The Board has held that a union’s failure to state in a
certification petition that “it has requested recognition and the
employer has declined” may be cured at the representation
hearing. Aria Resort & Casino, LLC, 363 NLRB No. 24, at 1
(2015). Similarly, at least one court of appeals has concluded
that “it would be [a] senseless technicality” to require dismissal
“where the demand and refusal of recognition [is] established
at the hearing itself.” NLRB v. Superior Cable Corp., 246
F.2d 539, 540 (4th Cir. 1957) (per curiam). We see no good
reason to part company with the Board and a sister circuit on
this issue, especially in view of the deference we owe the
Board’s interpretation of its own regulation. Rush Univ. Med.



    7
          The lack of a text-mandated consequence in section
102.61(a) distinguishes it from section 102.62(d), which the casinos
also cite. Section 102.62(d) provides that an employer’s violation
of certain voting procedures “shall be grounds for setting aside the
election whenever proper and timely objections are filed.” Section
102.62(d) thus makes section 102.61(a)’s silence more deafening:
the Board plainly “knows how to” mandate a particular remedy
“when it wants to.” Atl. Sounding Co. v. Townsend, 557 U.S. 404,
416 (2009) (internal quotation omitted).
                               15
Ctr. v. NLRB, 833 F.3d 202, 206-07 (D.C. Cir. 2016); see Auer
v. Robbins, 519 U.S. 452, 461 (1997).

               B. THE TECHS’ GUARD STATUS

     That brings us to the gravamen of the case. Are the
casinos’ surveillance technicians “guards” under section
9(b)(3) of the Act? Because the question is predominantly
factual, Burns Int’l Sec. Servs., 278 NLRB at 569, we will
disturb the Board’s determination only if it is “[un]supported
by substantial evidence on the record considered as a whole,”
29 U.S.C. § 160(e), (f); see Local 851, Int’l Bhd. of Teamsters
v. NLRB, 732 F.2d 43, 44 (2d Cir. 1984) (per curiam). The
standard is deferential but not abject: “We may not find
substantial evidence merely on the basis of evidence which in
and of itself justified the Board’s decision, without taking into
account contradictory evidence or evidence from which
conflicting inferences could be drawn.” NLRB v. Tito
Contractors, Inc., 847 F.3d 724, 732-33 (D.C. Cir. 2017)
(internal quotations and brackets omitted); see Universal
Camera Corp. v. NLRB, 340 U.S. 474, 488 (1951) (“The
substantiality of evidence must take into account whatever in
the record fairly detracts from its weight.”).

                      1. Section 9(b)(3)

    We cannot properly appraise the evidence of the techs’
guard status without first understanding what a guard is. So
“[w]e begin, as we must, with the text of the statute.”
NetCoalition v. SEC, 715 F.3d 342, 348 (D.C. Cir. 2013).
Section 9(b)(3) of the Act precludes the Board from

       decid[ing] that any unit is appropriate for
       [collective-bargaining] purposes if it includes,
       together with other employees, any individual
       employed as a guard to enforce against
                                16
        employees and other persons rules to protect
        property of the employer or to protect the safety
        of persons on the employer’s premises; but no
        labor organization shall be certified as the
        representative of employees in a bargaining unit
        of guards if such organization admits to
        membership, or is affiliated directly or
        indirectly with an organization which admits to
        membership, employees other than guards.

29 U.S.C. § 159(b)(3). The Board concedes that the Union
“admits to membership . . . employees other than guards,” id.,
and that the Union therefore cannot represent the techs if they
are guards, Br. of Resp’t 23; see Truck Drivers Local Union
No. 807 v. NLRB, 755 F.2d 5, 8 (2d Cir. 1985) (noting that
second clause of section 9(b)(3) “denies” union representing
non-guards “the right to be certified as a representative of a unit
of guards”). The question, then, is whether a tech is an
“individual employed as a guard to enforce against employees
and other persons rules to protect property of the employer or
to protect the safety of persons on the employer’s premises.”
29 U.S.C. § 159(b)(3).

     As a threshold matter, the casinos contend that a tech is a
guard if he is an “individual employed . . . to enforce . . . rules
to protect property of the employer” or if he is an “individual
employed . . . to protect the safety of persons on the employer’s
premises.” On the casinos’ interpretation, an employee who
protects patron safety can be a guard even if he does not
“enforce . . . rules.” The casinos forfeited that contention by
waiting until their reply brief to advance it. Bartko v. SEC,
845 F.3d 1217, 1225 n.7 (D.C. Cir. 2017). In any case, their
interpretation is unsound. It ignores the “rule of the last
antecedent,” under which we presume—absent indicia to the
contrary—that a modifier does not reach back to a previous
                               17
phrase if it can be read to modify a more proximal one.
Barnhart v. Thomas, 540 U.S. 20, 26 (2003) (internal quotation
omitted). In section 9(b)(3), the phrase “to protect the safety
of persons on the employer’s premises” does not reach back to
modify “individual employed as a guard”; instead it describes
the “rules” “enforce[d]” by that individual. After all, the same
sentence first mentions “rules to protect property of the
employer.” 29 U.S.C. § 159(b)(3) (emphasis added). It
makes sense to read the second iteration of “to protect” in
parallel fashion — i.e., to modify “rules” just as the first
iteration of “to protect” does. Cf. Mills Music, Inc. v. Snyder,
469 U.S. 153, 164-65 (1985) (“It is logical to assume that the
same word has the same meaning when it is . . . used earlier in
the same sentence.”). In short, some guards enforce rules to
protect the employer’s property and other guards enforce rules
to protect people on the premises. But an employee cannot be
a guard unless he enforces rules, be they the former kind or the
latter (or both).

     Because a tech is a guard only if he “enforce[s] . . . rules”
to protect the casinos’ property or patrons, we examine the
meaning of “enforce.” The leading law dictionary gives it a
broad definition: to “enforce” rules is “[t]o give force or effect
to” them. BLACK’S LAW DICTIONARY 645 (10th ed. 2014).
Similarly, the Board has long construed the concept “very
broadly” in a manner that does not require “personal
confrontation.” McDonnell Aircraft Co. v. NLRB, 827 F.2d
324, 327 (8th Cir. 1987) (citing Board cases). In Wright
Memorial Hospital, 255 NLRB 1319 (1980), for instance, the
Board concluded that ambulance drivers who were “on the
lookout for fire, theft, vandalism, and unauthorized personnel”
were guards. Id. at 1320. In the Board’s view, it did not
matter that when the drivers “discover[ed] an irregularity or
violation,” they took “no action on their own” but instead
informed a department head. Id. The Board deemed it
                                 18
“sufficient” that the drivers had “responsibility to observe and
report infractions, as this is an essential step in the procedure
for enforcement of hospital rules.” 8 Id.; see id. (“It is
immaterial that [the drivers] do not themselves enforce these
rules.”).

     The Board applied the same expansive interpretation in
MGM Grand Hotel, 274 NLRB 139 (1985). It held that the
operators of an electronic fire and security system at a Las
Vegas hotel were guards. Id. at 139-40. Two operators per
shift “monitor[ed] door exit alarms, stairwell motion detectors,
a watch tour system, and other systems.” Id. at 139. The
operators were only to observe and report; they left it to
security officers to “deal[] with cheating, injury, theft,
misconduct, and illness.” Id. Much as in Wright Memorial
Hospital, the Board reasoned that the operators’ lack of direct
contact with wrongdoers did “not detract from their guard
status” because they performed “an essential step in the
procedure for the enforcement of the employer’s rules.” Id. at
140 n.10 (brackets omitted) (quoting A.W. Schlesinger
Geriatric Ctr., 267 NLRB 1363, 1364 (1983)).

    Congressional intent, discernible from plain language,
supports the broad interpretation in Wright Memorial Hospital
and MGM Grand Hotel. The statute provides that a guard is
someone who enforces rules “against employees and other
persons.” 29 U.S.C. § 159(b)(3) (emphasis added). The
Congress’s purpose in passing section 9(b)(3) was “to
minimize the danger of divided loyalty that arises when a guard

    8
        The Board’s expansive interpretation has led to guard status
for a diverse array of employees, not only quintessential guards like
security officers. See McDonnell Aircraft, 827 F.2d at 326 (citing
cases involving, e.g., “unarmed courier service drivers,” “fitting
room checkers,” “timekeepers” and “receptionists”).
                               19
is called upon to enforce the rules of his employer against a
fellow union member.” Drivers, Chauffeurs, Warehousemen
& Helpers v. NLRB, 553 F.2d 1368, 1373 (D.C. Cir. 1977)
(Drivers & Chauffeurs); see BPS Guard Servs., Inc. v. NLRB,
942 F.2d 519, 526 (8th Cir. 1991) (“danger of divided loyalty”
is “measuring stick of Section 9(b)(3) status” (internal
quotation omitted)). And monitoring one’s fellow union
members can result in conflicts of interest without personal
confrontation.

     In its brief and at oral argument, the Board suggested the
Congress’s purpose is implicated only “during periods of
strikes or labor unrest.” Br. of Resp’t 23-24; see Oral Arg.
Recording 23:29-23:39 (“[T]he question of divided loyalty is
actually as to whether these guards would, say, refuse to cross
a picket line or refuse to actually enforce a rule against another
employee.”); id. at 27:01-27:05 (“[T]he policy stems from
workplace disputes . . . .”). Granted, the Congress “may have
had plant guards primarily in mind” when it enacted section
9(b)(3), inasmuch as it was “[r]eacting to” United States
Supreme Court cases involving plant-protection employees.
Drivers & Chauffeurs, 553 F.2d at 1373 (internal quotation
omitted) (citing NLRB v. Jones & Laughlin Steel Corp., 331
U.S. 416 (1947); NLRB v. E.C. Atkins & Co., 331 U.S. 398
(1947)). But as we pointed out in Drivers & Chauffeurs,
nothing in the statutory language suggests the Congress “was
blind to the potential for conflict inherent in [other]
employment contexts.” Id.; see id. at 1373-74 n.11 (no
indication “that Congress intended to draft a provision limited
to the facts of” Jones & Laughlin and Atkins). And, notably,
neither Wright Memorial Hospital nor MGM Grand Hotel
involved plant protection or labor unrest.
                                20
                 2. The evidence as a whole

    With the foregoing principles in mind, we turn back to the
record evidence. Taken as a whole, it demonstrates that the
techs perform “an essential step in the . . . enforcement” of rules
to protect the casinos’ property and patrons, including
enforcement against their fellow employees. MGM Grand
Hotel, 274 NLRB at 140 n.10 (internal quotation omitted);
Wright Mem’l Hosp., 255 NLRB at 1320.

     To recap just the highlights, the techs maintain
comprehensive camera coverage of each resort, including the
ever-changing gaming floor; they control access to all sensitive
areas of each casino and have access to all areas themselves;
they maintain alarm systems for the most valuable property in
each casino; and they help spy on fellow employees suspected
of misconduct. The Regional Director minimized these duties
because they require “mak[ing] no rounds” and “watch[ing] for
nothing other than issues affecting the surveillance system.”
JA 439, 881. The Board “agree[d]” with the Regional
Director and discounted the fact that the techs’ duties are “an
integral part of a larger security system.” JA 443 n.1, 885 n.1
(citing Wells Fargo Alarm Servs., 533 F.2d at 124; Am. Dist.
Tel. Co., 160 NLRB at 1138). We see at least four problems
with the Board’s analysis.

     First, it gives no weight to evidence that the surveillance
operators and security officers in the monitor rooms cannot
properly do their jobs without the techs. See, e.g., Mirage Tr.
115 (Q: “[C]an the surveillance operator[s] perform their job
without the surveillance techs?” A: “No.”); id. at 217 (Q: “Can
the security department perform its function . . . without the
surveillance techs?” A: “No.”). That the techs do not
themselves observe, report and respond to misconduct is
therefore not dispositive: they are “essential” to the process.
                              21
MGM Grand Hotel, 274 NLRB at 140 n.10; Wright Mem’l
Hosp., 255 NLRB at 1320.

     Moreover, the surveillance operators and security officers
cannot watch every live camera feed. That fact heightens the
importance of stored footage, which the techs aid in extracting;
it also helps illustrate the deterrent function that the cameras
serve even apart from the monitor-room operators and officers.
Consider Bellagio’s frequent tournaments, like the $500,000
baccarat tournament it held in June 2015. See supra note 2.
In such tournaments, players face off against one another in an
attempt to win money from a sizable prize pool. It is not
“unheard of” for a player to cheat by “pilfer[ing] chips” from
an opponent when no one is looking. Bellagio Tr. 83.
Because the casino does not post a security officer to each
table, “the cameras are the sole means of detecting that kind of
theft.” Id. at 84. If the surveillance operators in the monitor
room do not see the misconduct when it occurs, the stored
footage can be reviewed afterward to resolve any dispute. Just
as significantly, the cameras help “prevent” such disputes in
the first place because the players know they are being watched
and are less likely to cheat than they would be otherwise. Id.
at 83; see id. at 126 (“We’re in a casino. . . . Everybody’s
basically aware . . . that cameras are present.”).

     In short, camera coverage protects the players’ property
and safety. This commonsense observation applies similarly
to the casinos’ property: the existence of the camera coverage
discourages dealer dishonesty and encourages dealer accuracy,
just as the presence of the alarm system deters robbery.

     The techs are critical to the deterrence because they are
critical to the technology. The techs, not the surveillance
operators and security officers, investigate any tampering with
the cameras — which are themselves casino property. The
                                22
techs, not the operators and officers, coordinate with regulators
to maintain conforming coverage and ensure the continued
validity of the casinos’ gaming licenses. The Board does not
argue that the full range of the techs’ work could just as easily
be performed by other personnel such as the operators or
officers. Nor could such an argument succeed on this record:
the surveillance and security networks, comprised of high-tech
cameras and a “really fancy” “s[o]uped-up” computer system,
Mirage Tr. 54, are complicated enough that the techs train the
operators and officers on how to use them.

       Second, the Board gives too little weight to the type of
employer we are discussing. In the agency proceedings it
invoked two cases, respectively 41 and 51 years old, that
necessarily did not involve ultramodern luxury casinos. JA
443 n.1, 885 n.1 (citing Wells Fargo Alarm Servs., 533 F.2d at
124; Am. Dist. Tel. Co., 160 NLRB at 1138). In MGM Grand
Hotel, decided in 1985, the Board itself distinguished both
cases, partly because they had “not contemplated” the
“technological advance” embodied in MGM’s “vastly
sophisticated” security system. 274 NLRB at 140 & nn.8-9.
That observation applies with greater force 32 years later to
surveillance and security networks that are more sophisticated
still.

     The casinos’ networks protect high-end jewelry, priceless
art, stockpiles of cash and the personal safety of revelrous
guests who are not always vigilant regarding their own
wellbeing. In that regard, the casinos are nigh sui generis.
The closest analog we can think of is a bank.9 Cf. Mirage Tr.

    9
        Indeed, for some purposes under United States Code title 31
(“Money and Finance”), a licensed luxury casino is deemed a
“financial institution” much like a bank or credit union. See 31
U.S.C. § 5312(a)(2)(X).
                               23
58 (main cage is “like our bank”); Bellagio Tr. 93 (“There’s [a]
. . . lot of money in the cage.”). But even a bank does not have
to contend with scores of live transactions every instant in a
charged entertainment atmosphere. In this unusual setting,
where all-encompassing surveillance is the paramount
protector, the Board assigns too much weight to the fact that
the techs do not “perform traditional guard functions,” Br. of
Resp’t 30, such as carrying weapons, id. at 8-9, 25, and
“mak[ing] rounds,” JA 439, 881.

     Third, the Board does not properly account for the fact that
the techs can control what surveillance operators and security
officers see in the monitor rooms. They likewise control
which employees can enter “sensitive area[s]” like the server
room, the monitor rooms, the art gallery, executive offices,
count rooms and the main casino cage. Bellagio Tr. 89. The
techs thereby enforce—i.e., “give . . . effect to,” BLACK’S LAW
DICTIONARY, supra, at 645—their supervisors’ rules for
protecting the casinos’ most valuable property. Other courts
and the Board itself have indicated that control over access to
physical property is relevant to guard status. See, e.g., Local
851, Int’l Bhd. of Teamsters, 732 F.2d at 44 (drivers were
guards where, inter alia, they were “often given keys to the
premises and security vaults of customers”); Wright Mem’l
Hosp., 255 NLRB at 1320 (ambulance drivers were guards
where, inter alia, they “check[ed] to see that doors [were]
locked”). We see no basis for a different approach here.

     The Board ignores that, because of the techs’ know-how
and access, the casinos must put “quite a bit of trust . . . in
[their] integrity,” Bellagio Tr. 138, and subject them to
stringent background checks.          It does not require a
screenwriter’s imagination to appreciate the risks of sabotage:
the record is replete with testimony about how a dishonest tech
might realistically abuse his position at the expense of his
                                24
employer. See, e.g., id. at 102, 251-52 (without need for
“anyone’s approval,” tech could “maliciously” “shut cameras
off,” “prevent [them] from recording” or “delete specific
periods of time in the recording stream”); see also, e.g., Mirage
Tr. 119-20, 248-49 (without “being detect[ed],” tech could
enter sensitive areas or grant unauthorized access to others “at
just the push of a button”).

     The Board argues that “[t]he potential for sabotage isn’t
enough to make [a tech] a guard.” Oral Arg. Recording 32:10-
32:15. But even assuming the potential for sabotage does not
suffice for guard status, the authority, access and trust conferred
on the techs are relevant. See, e.g., Local 851, Int’l Bhd. of
Teamsters, 732 F.2d at 44 (drivers were guards because, inter
alia, they were “entrusted with a wide variety of valuable
commodities” and were “subjected to security clearance”);
Burns Int’l Sec. Servs., 278 NLRB at 569 (guard status may
“depend largely on the extent to which [the employee]
protect[s] . . . property”).

     Fourth, the Board gives no weight to the crucial fact that
the techs help enforce rules against their coworkers, most
obviously during special operations. In a special operation, a
tech installs a secret camera in—or covertly locks an existing
camera onto—a coworker’s work area so that other
surveillance and security personnel can spy on the targeted
employee. In denigrating the tech’s role as “limited,” JA 438-
39, 881, the Regional Director overlooked evidence that the
tech is essential to the operation, Bellagio Tr. 222 (Q: “Would
your investigators be able to perform the types of investigations
that they conduct . . . without video surveillance?” A: “No.”).
His analysis also overlooked that the tech is expected to
maintain the secrecy of the operation, including by cutting off
video coverage to other employees and, if necessary, lying to
them about it.
                               25
     The tech’s duties in a special operation squarely implicate
section 9(b)(3)’s aim of “minimiz[ing] the danger of divided
loyalty that arises when a guard is called upon to enforce the
rules of his employer against a fellow union member.”
Drivers & Chauffeurs, 553 F.2d at 1373. The operation can
lead to serious consequences for the target employee, including
termination and potentially prosecution. If the Union were to
represent both the techs and their target colleagues, the techs
might well feel pressure to tip off fellow Union members about
particular operations.

     The Regional Director saw “[n]o evidence . . . that techs
know the identity of the persons being investigated.” JA 436.
We read the record differently. Although the techs typically
are not given the target employee’s name, they are given
“[s]pecifics” like the “nature” of the misconduct, “what kind of
employee” is suspected of it and where it is occurring. Mirage
Tr. 105-06; see id. at 164, 190, 195 (tech typically knows why
he is setting up coverage in specific area); Bellagio Tr. 105 (he
is typically “given details”). That information, it seems to us,
would suffice for a conflicted tech to thwart a proper
investigation.

     The Board characterizes wrongful disclosure of such
information as a mere “possibility.” Br. of Resp’t 40. But
Section 9(b)(3) is meant “to minimize the danger of divided
loyalty.” Drivers & Chauffeurs, 553 F.2d at 1373 (emphasis
added). The focus is on minimizing temptation, pressure and
conflict, not on whether the tech will in fact betray the casino.
NLRB v. Brinks, Inc., 843 F.2d 448, 454 (11th Cir. 1988) (under
section 9(b)(3), “the realistic potential for divided loyalties
warrants the complete separation of guard and non-guard
unions” (emphasis in original)); see 29 U.S.C. § 151 (Act is
meant to alleviate “industrial strife”).
                                 26
                              *****
    Considering the record as a whole, we agree with the
casinos: the techs are guards under section 9(b)(3) of the Act
and can be represented only by an all-guard union. Because
the Union represents employees other than guards, it was
improperly certified as the techs’ representative and the Board
erred in concluding that the casinos unfairly refused to bargain.
Accordingly, we grant the casinos’ petitions for review, deny
the Board’s cross-applications for enforcement and vacate the
Board’s May 2016 decisions and orders.10

                                                        So ordered.

     10
          Our dissenting colleague would defer to the Board on the
theory that it could reasonably decide the techs do not “compel
obedience to” the casinos’ rules. Dissent at 2 (quoting BLACK’S
LAW DICTIONARY, supra, at 645) (emphasis omitted). But the
Board’s own cases—which take a “very broad[]” view of guard
status—do not require compulsion of obedience. McDonnell
Aircraft Co., 827 F.2d at 326-27 (citing Board cases). After all,
ambulance drivers, fitting room checkers, timekeepers, receptionists
and casino surveillance operators are all guards even though they do
not affirmatively compel obedience to any rules. See supra note 8
and accompanying text; Br. of Resp’t 30 (conceding that casinos’
“surveillance operators . . . perform traditional guard functions”).
The inquiry turns not on compulsion or personal confrontation, see
Dissent at 2 (“direct role”), but on whether a putative guard performs
“an essential step in the procedure for the enforcement of the
employer’s rules.” MGM Grand Hotel, 274 NLRB at 140 n.10
(brackets and internal quotation omitted); see Wright Mem’l Hosp.,
255 NLRB at 1320. We cannot defer to an agency decision that
ignores extensive unrebutted evidence satisfying the agency’s own
governing standard. And, respectfully, the evidence is indeed
extensive that the techs’ duties go well beyond old-fashioned
installation, inspection and repair. Dissent at 1-2 (citing Am. Dist.
Tel. Co., 160 NLRB at 1134, 1138 (1966)).
     SRINIVASAN, Circuit Judge, concurring in part and
dissenting in part: For the reasons explained in Part II.A of
the court’s opinion, I agree that the failure of the Union
representing the surveillance techs to seek recognition from
the Casinos prior to filing its certification petitions does not
require the petitions’ dismissal. I respectfully disagree,
though, with my colleagues’ conclusion in Part II.B that the
Board was compelled to conclude that the techs are “guards”
within the meaning of Section 9(b)(3) of the National Labor
Relations Act.

     We have explained that, when reviewing the Board’s
determinations about which employees constitute statutory
guards, “[w]e must be particularly wary not to substitute
judgment where . . . the agency’s expertise illuminates the
meaning of an open-ended statutory term.” Drivers,
Chauffeurs, Warehousemen and Helpers, Local 71 v. NLRB,
553 F.2d 1368, 1374 (D.C. Cir. 1977). Here, as my
colleagues explain, ante at 17, whether the techs qualify as
guards under the Act turns on whether they “enforce rules” on
behalf of the Casinos. 29 U.S.C. § 159(b)(3).

     In my view, the Board might have reasonably
determined, as my colleagues do, that the techs’ role in
maintaining the Casinos’ surveillance equipment bears a
sufficient connection to the enforcement of Casino rules to
render them guards under the statute. But I also believe the
Board acted reasonably in reaching the opposite conclusion.
Whatever else the techs’ duties entail, their responsibilities
undisputedly do not encompass observing, reporting, or
restraining infractions of the Casinos’ rules. I would sustain
the Board’s conclusion that employees who lack those duties
do not “enforce rules” and thus do not qualify as statutory
guards.

    More than a half century ago, the Board staked out its
position that responsibility “for new installations, periodic
                              2
inspections, and maintenance and repairs of . . . protective
equipment” does not render an employee a guard under the
NLRA. Am. Dist. Tel. Co., 160 NLRB 1130, 1134, 1138
(1966). The Board has maintained that view ever since. For
instance, in MGM Grand Hotel, the Board, while indicating
that employees who “possess and exercise responsibility to
observe and report infractions” qualify as guards, 274 NLRB
139, 140 n.10 (1985) (quoting A.W. Schlesinger Geriatric
Ctr., 267 NLRB 1363, 1364 (1983)), explicitly distinguished
such employees from ones “involved [in] the installation and
maintenance of certain electronic security devices,” id. at 140
n.8. The Board adhered to that line in this case.

     The Board’s understanding of what it means to “enforce
rules” is entirely consistent with those words’ ordinary
meaning. My colleagues rely on the definition of “enforce” in
Black’s Law Dictionary. Even that definition, though, readily
accommodates the Board’s interpretation. It is true that the
definition’s first entry speaks in terms of giving “force or
effect” to a rule. BLACK’S LAW DICTIONARY 645 (10th ed.
2014). And had the Board determined that the techs qualify
as guards, it could have attempted to reason that, by
maintaining surveillance equipment, the techs help “give
force or effect to” the Casinos’ rules. But in reaching the
opposite conclusion—that the techs fail to qualify as guards—
the Board maintained full consistency with the definition: the
Board could reason that the techs play an insufficiently direct
role in “giving force or effect” to the Casinos’ rules.
Moreover, the definition states in full: “[t]o give force or
effect to (a law, etc.); to compel obedience to.” Id. (emphasis
added). The Board’s conclusion that employees qualify as
guards only if they observe, report, or restrain infractions
draws support from a conception of “enforce” tied to
“compelling obedience” to rules.
                              3
     Here, because the techs’ duties do not include those
functions, I would sustain the Board’s conclusion that the
techs may be part of the same union as the Casinos’ non-
guard employees. That conclusion is unaffected by the techs’
role in “special operations” investigating co-workers
suspected of misconduct. In that context, the techs’ duties are
confined to ensuring the proper positioning of surveillance
cameras and retrieving the footage. Ante at 9. Other
employees monitor the feed, review the footage, and, if
warranted, interview or confront the subject of the
investigation. In that sense, the techs’ responsibilities in
connection with investigations of co-workers parallel their
duties with regard to surveillance of Casino patrons. If those
functions fail to amount to enforcement of the Casinos’ rules
when directed at patrons, they likewise fall short of
enforcement when directed at co-employees. Respectfully, I
therefore believe the Board acted within its discretion in
concluding that the techs’ duties do not constitute
enforcement of rules within the meaning of the NLRA.
