In the

    United States Court of Appeals
                For the Seventh Circuit
                    ____________________
No. 15-3870
STEPHEN D. WESBROOK, PH.D.,
                                                Plaintiff-Appellant,

                                v.

KARL J. ULRICH, M.D., and EDWARD A. BELONGIA, M.D.,
                                      Defendants-Appellees.
                    ____________________

        Appeal from the United States District Court for the
                   Western District of Wisconsin.
       No. 13-cv-494-wmc — William M. Conley, Chief Judge.
                    ____________________

  ARGUED SEPTEMBER 8, 2016 — DECIDED OCTOBER 20, 2016
                    ____________________

    Before WOOD, Chief Judge, and KANNE and HAMILTON, Cir-
cuit Judges.
   HAMILTON, Circuit Judge. This appeal presents issues un-
der Wisconsin law on the scope of tort remedies a fired at-will
employee might have not against his employer but against in-
dividual supervisors and co-workers. Plaintiff Dr. Stephen
Wesbrook, a former employee of the Marshfield Clinic Re-
search Foundation, brought this lawsuit against Dr. Edward
2                                                    No. 15-3870

Belongia, a former colleague, and Dr. Karl Ulrich, the chief ex-
ecutive officer of the Marshfield Clinic. Wesbrook contends
that Belongia and Ulrich tortiously interfered with his at-will
employment, engineering his termination by publishing de-
famatory statements about him to the Marshfield Clinic board
of directors.
    The district court granted summary judgment to the de-
fendants. Wesbrook has appealed. Wisconsin tort law governs
this case, which is within the federal courts’ diversity jurisdic-
tion under 28 U.S.C. § 1332. The undisputed facts show that
the defendants’ statements about the plaintiff were true or
substantially true and therefore privileged. Under Wisconsin
law, an at-will employee cannot recover from former co-work-
ers and supervisors for tortious interference on the basis of
their substantially truthful statements made within the enter-
prise, no matter the motives underlying those statements. We
therefore affirm the judgment of the district court.
I. Factual and Procedural Background
   We review de novo the district court’s grant of summary
judgment to the defendants. Boston v. U.S. Steel Corp., 816 F.3d
455, 462 (7th Cir. 2016). To prevail on summary judgment, the
defendants must show that there is no “genuine dispute as to
any material fact” and that they are entitled to judgment as a
matter of law. Fed. R. Civ. P. 56(a). Like the district court, we
must construe all evidence and draw all reasonable inferences
in favor of the non-moving party, plaintiff Wesbrook. See
Woods v. City of Berwyn, 803 F.3d 865, 869 (7th Cir. 2015).
No. 15-3870                                                  3

   A. The Parties
     This case arises from strategic disagreements and a power
struggle within the Marshfield Clinic, a prominent not-for-
profit health care system headquartered in Marshfield, Wis-
consin. At all relevant times, defendant Ulrich served as pres-
ident and chief executive officer of the Clinic and as a member
of its board of directors. One of the Clinic’s divisions is the
Marshfield Clinic Research Foundation (“the Research Foun-
dation”), which is the largest private medical research insti-
tute in Wisconsin. During the years in question, Dr. Humberto
Vidaillet served as director of the Research Foundation. Plain-
tiff Wesbrook was deputy director from 2006 until his termi-
nation took effect January 2, 2012. Defendant Belongia was
also employed at the Research Foundation as a senior re-
search scientist and research center director.
   B. Conflict at the Research Foundation
    Proceedings in the district court narrowed Wesbrook’s al-
legations against Ulrich and Belongia to a claim for tortious
interference with his employment based on four statements
that Ulrich published to the Clinic’s board of directors: (1)
Wesbrook coerced Research Foundation employees he super-
vised; (2) some Research Foundation employees filed com-
plaints against Wesbrook; (3) Wesbrook breached a perfor-
mance improvement plan; and (4) a prominent supporter of
the Clinic spoke with over forty people associated with the
Clinic and the Research Foundation, many of whom com-
plained about Wesbrook. As explained below, each of these
statements was substantially true, but some further factual
background is needed to understand this litigation and the
implications of the parties’ legal positions.
4                                                  No. 15-3870

    Wesbrook’s tenure as deputy director of the Research
Foundation was marked by internal conflict. Problems first
surfaced during his candidacy for the deputy position. One
member of the interview committee remarked: “I would be
reluctant to hire someone who has so clearly and dramatically
polarized the basic scientists that constitute the ‘core’ of the
research organization.” (Wesbrook was then already known
to the committee; he had worked at the Research Foundation
previously, from 2000 to 2005.) Another employee threatened
to resign if Wesbrook were rehired and followed through on
that threat shortly after Wesbrook returned.
    Though Wesbrook had a good working relationship with
his immediate supervisor, Vidaillet, his relationship with Ul-
rich was stormy. Ulrich wanted to change the Clinic’s organi-
zational structure. On several occasions between May 2008
and September 2011, Ulrich tried but failed to reduce the in-
dependence of the Research Foundation’s board of trustees
and to transfer oversight of the Research Foundation’s en-
dowment to the Clinic’s executive leadership. Collaborating
with Vidaillet and the Research Foundation’s trustees,
Wesbrook helped defeat these efforts.
    In July 2008, Ulrich also circulated a shareholder proposal
to switch the Clinic from its democratic, physician-led gov-
ernance structure to a more conventional corporate model.
According to Vidaillet, the proposal would have resulted in
Ulrich’s automatic selection as interim CEO, a position that
would have given him substantial influence over appoint-
ments of new board members. Vidaillet vigorously opposed
Ulrich’s plan, and he recruited Wesbrook to help his campaign
No. 15-3870                                                                 5

against it. Ulrich’s proposal was defeated, as were similar pro-
posals in 2009 and 2011. 1
    C. Employee Complaints
    The undisputed evidence also shows conflict and tension
within the Research Foundation where Wesbrook was deputy
director. In March 2010, an employee alerted David Keefe, di-
rector of human resources, that Wesbrook and Vidaillet had
been making derogatory comments about Research Founda-
tion scientists, prompting some of them to resign. Then an-
other employee alerted the Research Foundation’s board of
trustees that fifteen scientists had left the foundation since
2006. On April 13, 2010, the Clinic’s board of directors asked
the human resources department to investigate why the fif-
teen scientists had left and whether there was a “culture of
intimidation” at the Research Foundation.
   Keefe investigated. He spoke with nine of the fifteen sci-
entists who had left the Research Foundation. In response to



    1 As a third example of his conflict with Ulrich, Wesbrook points to
his and Vidaillet’s efforts in the fall of 2011 to persuade the Clinic’s board
of directors to investigate possible Medicare fraud in relation to a contract
that Ulrich had executed. The board declined to undertake the investiga-
tion. While Wesbrook refers to himself in this lawsuit as a “whistle-
blower,” there is no indication that he took his concerns outside the Clinic
organization. Nevertheless, Wesbrook argues that Ulrich had it out for
him after he “assisted in bring[ing] possible violations of law to the
Board’s attention.” We are not so convinced. As the district court noted,
“Wesbrook fails to tie this event to any alleged motive on the part of Ulrich
to seek his termination. Specifically, Wesbrook fails to point to evidence
that Ulrich opposed the investigation.” Wesbrook v. Ulrich, No. 13-cv-494-
wmc, 2015 WL 7871063, at *3 n.6 (W.D. Wis. Dec. 3, 2015). This appeal pre-
sents no issue concerning the legal rights of genuine whistleblowers.
6                                                  No. 15-3870

open-ended questions, several described Wesbrook’s manage-
ment style using words such as “cold, militaristic, harsh, re-
taliatory, abusive, negative, hostile, confrontational, out of
control, threatening, boot-camp-like, and contentious.” While
Keefe was investigating, other employees brought additional
concerns to Ulrich’s attention. One research scientist told Ul-
rich that Wesbrook’s management style was “oppressive” and
that he “retaliated against scientists who questioned or disa-
greed with his decisions.” Another scientist described
Wesbrook as “intimidating and vindictive” and blamed
Wesbrook for creating a “toxic” environment. An emeritus re-
search clinician told Ulrich that employees found Wesbrook
“intimidating and demeaning” and that they “feared retribu-
tion if they said anything that was contrary” to Wesbrook.
    Ulrich scheduled a meeting with Wesbrook for September
2, 2010. He planned to address Wesbrook’s management style
and the possible consequences of his behavior. On the morn-
ing of the scheduled meeting, Ulrich notified Vidaillet
(Wesbrook’s immediate supervisor) about his intentions for
the meeting. Vidaillet then told Wesbrook to take the day off,
and Wesbrook did so. In light of the complaints about
Wesbrook and his absence from the meeting, Ulrich fired
Wesbrook. However, at Vidaillet’s behest, and by the narrow
vote of nine to eight, the Clinic’s board of directors overruled
Ulrich and reinstated Wesbrook on September 7, 2010.
    While Wesbrook narrowly avoided termination in 2010,
students of organizational behavior will not be surprised to
learn that tensions at the Research Foundation continued to
simmer. In March 2011, three administrators of the founda-
tion’s research centers complained to Keefe in human re-
sources about Wesbrook’s micromanagement and his pattern
No. 15-3870                                                     7

of retaliation. In July, a veteran research scientist resigned be-
cause she “wanted to get away from Dr. Wesbrook.” Another
scientist resigned that same month. Before leaving, he spoke
with Belongia about the administrative environment at the
Research Foundation, which he characterized as “increas-
ingly adversarial” and plagued by “conflict, inaction, and
dysfunction.”
   D. The Belongia Letter
    In November 2011, Jordon Ott resigned from the Research
Foundation. She was a research administrator who reported
directly to Belongia. She told Belongia that her frustration
with Wesbrook was a “key factor” in her decision. Belongia
then sent a letter to Ulrich identifying four broad categories
of concern with Vidaillet’s and Wesbrook’s leadership of the
Research Foundation. This letter became the basis for
Wesbrook’s claim in this suit against Belongia.
    Belongia wrote that several scientists and staff had ex-
pressed their frustration to him in confidence, while others
had “already filed complaints with Human Resources regard-
ing the Deputy Director.” In Belongia’s words, Wesbrook had
also used “coercion and intimidation in his interactions with
scientists and administrators.” Belongia said that he could
“provide specific examples” and that other employees could
“corroborate this and provide other examples.”
   E. The Performance Improvement Plan, the Ulrich Chronology,
      and Wesbrook’s Termination
   In the summer of 2011, Ulrich had directed the Clinic’s
process improvement group to evaluate the time commitment
associated with Vidaillet’s position as director of the Research
8                                                    No. 15-3870

Foundation. During the evaluation, several employees volun-
teered complaints about Wesbrook, including that he had cre-
ated a hostile work environment and that employees feared
retaliation if they voiced their concerns. The Clinic’s board of
directors reviewed these findings at a September 6, 2011 meet-
ing. At the end of that meeting, the board directed Vidaillet
and Ulrich to develop jointly a performance improvement
plan for Wesbrook.
    Following the board meeting, Ulrich coordinated with
Pauline Pritzl, a human resources manager, to draft an im-
provement plan suitable for Wesbrook’s position. Ulrich and
Pritzl presented the draft to Vidaillet, who disagreed with it
and prepared his own version. At a November 10, 2011 meet-
ing, Vidaillet distributed his proposed improvement plan to
Ulrich and Pritzl. Ulrich said that only one plan would be im-
plemented, but he told Pritzl to incorporate any relevant sec-
tions of Vidaillet’s proposal into the final draft. Pritzl did so,
and Ulrich forwarded the integrated document to Wesbrook.
   On December 8, 2011, Ulrich, Pritzl, Vidaillet, and
Wesbrook met to review the proposed improvement plan.
During the meeting, Wesbrook handed out a memorandum
in which he responded only to those concerns identified in
Vidaillet’s version of the plan. Ulrich asked Pritzl, Keefe, and
another human resources professional to review Wesbrook’s
memorandum. Each agreed it was not an appropriate re-
sponse. The next day, Ulrich told Wesbrook that he could ei-
ther resign or face termination. Ulrich then placed Wesbrook
on administrative leave pending board review.
   On December 19, 2011, Ulrich drafted a nine-page “Chro-
nology” outlining Wesbrook’s troubled history as deputy di-
No. 15-3870                                                    9

rector, including his conduct during the performance im-
provement process. Ulrich sent the Clinic’s board of directors
a copy of the Chronology and Belongia’s November 2011 let-
ter. Ulrich also provided the board with a copy of a handwrit-
ten letter addressed to Vidaillet by Melvin Laird, a retired U.S.
Representative from Wisconsin and U.S. Secretary of Defense,
and a long-time supporter of the Marshfield Clinic. Laird’s let-
ter referred to a conversation in which Vidaillet had said he
thought he was about to be fired. Laird wrote back that he had
spoken with “over forty individuals” associated with the
Clinic. Based on his conversations, Laird concluded that the
problem at the Research Foundation was not Vidaillet but was
instead Wesbrook.
    After reviewing these documents and other submissions,
the Clinic’s board voted thirteen to two to support Ulrich’s de-
cision, up to and including termination of Wesbrook’s em-
ployment. Ulrich then fired Wesbrook effective January 2,
2012.
   F. District Court Decision
    In 2013, Wesbrook filed this suit accusing Ulrich, Belongia,
and two other former colleagues of tortiously interfering with
his employment. The district court allowed Wesbrook’s claims
against Ulrich and Belongia to proceed to discovery. Ulrich
and Belongia later moved for summary judgment.
    Wesbrook’s complaint had described the defendants’ “sus-
tained campaign” to have him fired, with allegations of “nu-
merous false and defamatory statements” and actions on
“multiple occasions … to interfere with [his] contract of em-
ployment.” By the summary judgment stage, Wesbrook’s the-
ory of the case had narrowed considerably. He focused on
10                                                    No. 15-3870

four allegedly false statements to the board of directors who
had approved his firing: Belongia’s observations that
Wesbrook “coerced” employees and that employees “filed”
complaints against him; Ulrich’s description of the perfor-
mance improvement process; and Laird’s reference to talking
with at least forty Research Foundation affiliates.
    The district court granted the defendants’ motion for sum-
mary judgment. Although the court acknowledged that
Wesbrook’s “evidence of internal strife within the Clinic is
strong, especially as it concerns Ulrich’s possible motives,”
Wesbrook v. Ulrich, No. 13-cv-494-wmc, 2015 WL 7871063, at *9
(W.D. Wis. Dec. 3, 2015), the court found that the undisputed
facts showed that each of the challenged statements was true
or at least substantially true. Ulrich’s motives were therefore
immaterial.
II. Analysis
     A. The Law of Tortious Interference
     Under Wisconsin law, a claim for tortious interference
with a contract requires proof of five elements: “(1) the plain-
tiff had a contract or a prospective contractual relationship
with a third party, (2) the defendant interfered with that rela-
tionship, (3) the interference by the defendant was intentional,
(4) there was a causal connection between the interference and
damages, and (5) the defendant was not justified or privileged
to interfere.” Briesemeister v. Lehner, 720 N.W.2d 531, 542 (Wis.
App. 2006). The parties dispute here the fifth element,
whether the defendants’ challenged statements were privi-
leged.
    Generally speaking, whether conduct is privileged from
tort liability is a fact-sensitive question that takes into account
No. 15-3870                                                     11

the “nature, type, duration and timing of the conduct,
whether the interference is driven by an improper motive or
self-interest, and whether the conduct, even though inten-
tional, was fair and reasonable under the circumstances.” Id.
at 543; see also Restatement (Second) of Torts § 767 (Am. Law
Inst. 1979) (listing seven factors). For instance, the “common
interest” conditional privilege, which offers some protection
for false statements in the workplace, may be forfeited “if the
defendant acted from ill will or an improper motive towards
the plaintiff.” Wolf v. F & M Banks, 534 N.W.2d 877, 885 (Wis.
App. 1995).
    Wisconsin law recognizes an important exception to the
ordinary multifactor inquiry about privilege. If a claim for tor-
tious interference is based on statements that are true, the
claim must fail as a matter of law. The Wisconsin Court of Ap-
peals observed in Mackenzie v. Miller Brewing Co. that the
“‘transmission of truthful information is privileged, does not
constitute improper interference with a contract, and cannot
subject one to liability for tortious interference with a contract’
or prospective contract.” 608 N.W.2d 331, 349 (Wis. App.
2000), aff’d, 623 N.W.2d 739 (Wis. 2001), quoting Liebe v. City
Finance Co., 295 N.W.2d 16, 18 (Wis. App. 1980). Likewise, the
drafters of the Restatement included section 772 as a “special
application of the general test” outlined in section 767: “There
is of course no liability for interference with a contract … on
the part of one who merely gives truthful information to an-
other.” Restatement (Second) of Torts § 772 cmts. a, b (Am.
Law Inst. 1979). Thus, while a defendant’s motive is often rel-
evant in deciding whether she tortiously interfered with a
plaintiff’s contract, motive is irrelevant when the defendant
spoke the truth.
12                                                          No. 15-3870

    Further, a statement may be substantially true—and thus
privileged—even if some fine splitting of semantic hairs
might leave room to argue about its literal truth. See Terry v.
Journal Broadcast Corp., 840 N.W.2d 255, 264 (Wis. App. 2013).
The Terry court explained: “It is not ‘necessary that the …
statement in question be true in every particular. All that is
required is that the statement be substantially true.’” Id., quot-
ing Lathan v. Journal Co., 140 N.W.2d 417, 423 (Wis. 1966).
    Terry and Lathan were defamation cases. We are aware of
no precedential Wisconsin decisions that have explicitly ex-
tended substantial truthfulness as a defense to tortious inter-
ference. 2 We see no principled reason, though, why the de-
fense would not apply with equal force in this context. In the
absence of contrary authority, we predict that the Wisconsin
Supreme Court would apply it. See Todd v. Societe Bic, S.A., 21
F.3d 1402, 1412 (7th Cir. 1994) (“Our task in a diversity case is
to predict what the state’s highest court would do if presented
with the same issue.”).
     B. The Defendants’ Truthful Statements
    Plaintiff Wesbrook’s claims against defendants Ulrich and
Belongia turn on the answer to one question: were the defend-
ants’ statements true or at least substantially true? The undis-
puted facts show that they were. Wesbrook bases his tortious
interference theory on four statements that Ulrich published
to the Clinic’s board of directors: (1) Belongia’s statement that


     2One non-precedential opinion did so. See Park Towne Dev. Corp. v.
Gotta Madison Assocs., 337 N.W.2d 856, 1983 WL 161457, at *3 (Wis. App.
1983) (“‘[T]he transmission of truthful information is privileged … and
cannot subject one to liability for tortious interference with a contract.’
Substantial truth is all that is required.”) (citations omitted).
No. 15-3870                                                   13

Wesbrook used coercion in his interactions with other em-
ployees; (2) Belongia’s statement that employees filed com-
plaints against Wesbrook; (3) Ulrich’s description of the per-
formance improvement plan; and (4) Laird’s statement that he
spoke with over forty people. Wesbrook’s quarrel with the
first two statements involves semantic hairsplitting. His claim
about the performance improvement plan misconstrues what
Ulrich actually said. And his criticism of Laird’s letter is both
unsupported by the record and immaterial.
       1. Coercion
    Wesbrook complains about Belongia’s assertion that
Wesbrook “used coercion and intimidation in his interactions
with scientists and administrators.” Not so, Wesbrook pro-
tests. While conceding that he may have intimidated his co-
workers, he claims he never coerced them. Coercion, Wesbrook
argues, “entails overt acts,” whereas “any individual may be
unintentionally intimidated by another’s personality, size,
knowledge or skill.” Wesbrook points to Belongia’s 2015 dep-
osition testimony acknowledging that he had not personally
been “coerced” by Wesbrook and could not recall a specific
example of an individual who had experienced such “coer-
cion.”
    The district court pointed out correctly that the terms “co-
ercion” and “intimidation” are often used interchangeably.
For instance, the American Heritage Dictionary of the English
Language (fifth edition) defines “coerce” as to “pressure, in-
timidate, or force (someone) into doing something.” Likewise,
Webster’s Third New International Dictionary of the English Lan-
guage defines “coerce” as to “restrain, control, or dominate,
14                                                         No. 15-3870

nullifying individual will or desire (as by force, power, vio-
lence, or intimidation).” 3
    The undisputed facts show that some of Wesbrook’s col-
leagues found him overbearing. As David Keefe in human re-
sources reported, former colleagues described Wesbrook’s
management style as, among other things, cold, militaristic,
confrontational, and contentious. One scientist described
Wesbrook as “intimidating and vindictive,” while another left
her position due in part to the “hostile treatment” she had re-
ceived from Wesbrook. A veteran clinician recounted com-
plaints from employees who “feared retribution if they said
anything that was contrary” to Wesbrook. It is undisputed
that Ulrich, Belongia, and the Clinic’s board of directors had
received this information. It strains credulity beyond the
breaking point to suppose that the board would have been
unmoved by these reports of Wesbrook’s bullying and retali-
ation but was finally spurred to action by a reference to “co-
ercion.” We will not split hairs so finely. Tort law does not de-
mand such artificial precision in ordinary use of language. Be-
longia’s statement that Wesbrook used “coercion and intimi-
dation” was at least substantially true, so the statement was
privileged as a matter of law.
         2. “Filed” Complaints
   Wesbrook next takes issue with Belongia’s assertion that
some Research Foundation scientists and staff had “already


     3 In paragraph 94 of his own proposed findings of fact, Wesbrook him-

self used the term “coerce” in the same way, without referring to threats
of physical force. He described one of Ulrich’s shareholder communica-
tions as a “ploy to coerce the shareholders into approving [his] reorgani-
zation plan.”
No. 15-3870                                                 15

filed complaints with Human Resources regarding the Dep-
uty Director.” Wesbrook contends this statement was false be-
cause no formal written complaints were actually “filed.” In
his deposition, Belongia admitted that he had “intended to
say” that employees had “complained to human resources”
and that in retrospect the word “filed” was “probably not the
optimal word to use.” Wesbrook contends that “filing” a com-
plaint necessarily “connotes starting a formal investigative
process … which could lead to some type of sanction against
the administrator or formal intervention on behalf of the ag-
grieved employee.” Conversely, “complaining”—according
to Wesbrook—is “akin to griping, blowing off steam, taking
advantage of a sounding board, or requesting advice about
how to deal with an issue.”
    Wesbrook offers no authority, linguistic or otherwise, sug-
gesting that tort liability should depend on his proposed dis-
tinction between “complaining” to human resources and “fil-
ing” a complaint with human resources. The distinction is un-
persuasive, particularly on this record. Undisputed evidence
shows that employees of the Research Foundation were not
simply “griping” to one another about Wesbrook. They met
with supervisors and human resources personnel to express
their concerns and, presumably, to seek some kind of resolu-
tion. Many had even chosen to resign to get away from
Wesbrook.
   The undisputed facts show that Belongia was aware of
growing dissatisfaction with Wesbrook’s leadership. His own
research administrator, Jordon Ott, was among those who de-
parted during the final months of Wesbrook’s tenure. By writ-
ing that some employees had “already filed complaints with
16                                                   No. 15-3870

Human Resources,” Belongia accurately reflected the circum-
stances at the Research Foundation as of November 2011. Be-
longia’s statement was at least substantially true, so it was
privileged as a matter of law.
       3. Performance Improvement Plan
    Wesbrook complains next about Ulrich’s description in his
Chronology of the performance improvement process. Ac-
cording to Wesbrook, Ulrich falsely “alleg[ed] that Wesbrook
had failed to comply with a performance improvement plan.”
This contention is a straw man. Ulrich made no such asser-
tion.
    In his Chronology, Ulrich acknowledged the decision by
the Clinic’s board of directors that he and Vidaillet should
jointly develop an improvement plan for Wesbrook. Ulrich
described meeting with Vidaillet and with Pauline Pritzl in
human resources to work on the plan. Ulrich noted that
Vidaillet prepared his own draft and that Ulrich instructed
Pritzl to incorporate relevant portions of that draft into the fi-
nal document. Ulrich also described the November 15, 2011
meeting with Wesbrook, in which Ulrich told Wesbrook that
there was only one improvement plan and “that was the one
that [Ulrich] had provided.” Finally, Ulrich recounted the De-
cember 8, 2011 meeting at which Wesbrook circulated his re-
sponse to the improvement plan and the later meeting in
which Ulrich gave Wesbrook the ultimatum to resign or be
fired.
   At no point in the Chronology did Ulrich assert that
Wesbrook failed to comply with his performance improve-
ment plan. Rather, it was Wesbrook’s deficient response to the
proposed plan that triggered his termination. The Clinic’s
No. 15-3870                                                 17

board of directors had instructed Ulrich and Vidaillet to pre-
pare a joint document, and according to Vidaillet, the board
had ordered that the “plan be brought back … for approval.”
That never happened. Instead, at an October 11, 2011 meeting,
the board decided that the “question of Wesbrook’s perfor-
mance improvement plan would be part of the Board’s sched-
uled March 2012 evaluation of [Vidaillet].” The board could
not have harbored any doubt about the status of Wesbrook’s
compliance with a performance improvement plan that it had
never approved.
    Ulrich’s account of the performance improvement process
was truthful and thus privileged as a matter of law. In addi-
tion, Wesbrook’s hypothetical non-compliance with an im-
provement plan that the Clinic’s board had never adopted
could not have caused his termination and so cannot serve as
the basis for a tortious interference claim. See Briesemeister,
720 N.W.2d at 542 (one element of a tortious interference
claim is “a causal connection between the interference and
damages”).
       4. Laird Letter
    Finally, Wesbrook contends that Ulrich gave the Laird let-
ter to the Clinic’s board of directors without properly verify-
ing its contents. Wesbrook asserts that Laird had “at best a
tenuous grasp on the circumstances regarding Wesbrook’s
and Vidaillet’s conflict with Ulrich and Belongia,” and
Wesbrook faults Laird for saying that he spoke with at least
forty Research Foundation affiliates, a statement Wesbrook
deems “incorrect.”
    In his deposition testimony, however, Laird insisted that
his letter was “factually correct.” Laird testified that he may
18                                                  No. 15-3870

have spoken with “a hundred” people, and he reiterated that
while his reference to forty people was an estimate, he proba-
bly spoke with more than forty people. To rebut Laird’s testi-
mony and present a genuine issue of material fact, Wesbrook
has offered no evidence, nothing more than raw speculation.
In any event, we do not understand how the number of peo-
ple Laird contacted could support Wesbrook’s theory of tor-
tious interference. Wesbrook has no evidence to dispute the
salient point, which is that a substantial number of Research
Foundation affiliates told Laird that their problem was not
with Vidaillet but with Wesbrook.
    We need not belabor the point. Wesbrook has failed to of-
fer any evidence that any material statement in the Laird letter
is untrue. The letter is therefore privileged as a matter of law.
     C. The Preston Decision
    Because the statements on which Wesbrook bases his
claims against Ulrich and Belongia were each true or substan-
tially true, we agree with the district court that no reasonable
jury could find tortious interference on this record.
Wesbrook’s argument to the contrary gains no additional trac-
tion by his attack on Preston v. Wisconsin Health Fund, 397 F.3d
539 (7th Cir. 2005), in which we addressed Wisconsin’s law of
tortious interference in the context of employment. For the
sake of completeness, we address Wesbrook’s Preston argu-
ment, which highlights the larger stakes here.
    In Preston, the former director of a dental clinic brought a
tortious interference claim against the CEO and another den-
tist claiming that the CEO’s decision to fire him had been
tainted by an improper motive. Id. at 540–41. (The CEO had
replaced Preston with the other dentist, with whom the CEO
No. 15-3870                                                             19

allegedly had a romantic relationship.) In affirming summary
judgment for the defendants, we explained that an employee
who alleges tortious interference by a co-worker or supervisor
must prove “both that the employer did not benefit from the
defendant’s act and that the act was independently tortious,
for example as fraud or defamation.” Id. at 544. Wesbrook
challenges that two-prong test. He contends that Preston im-
properly modified the elements of a tortious interference
claim under Wisconsin law, and he urges us to overrule Pres-
ton. For two reasons, we decline.
    First, the Wisconsin judiciary has given no indication that
it disagrees with Preston. In nearly twelve years since Preston
was decided, no Wisconsin court has disapproved or even dis-
tinguished it. 4 We do not lightly overturn circuit precedent,
and we give “considerable weight to prior decisions of this
court unless and until they have been overruled or under-
mined by the decisions of a higher court, or other supervening
developments.” Santos v. United States, 461 F.3d 886, 891 (7th
Cir. 2006) (citation omitted), aff’d, 553 U.S. 507 (2008). The state
courts are quite capable of signaling when they disagree with


    4  We know of only one non-precedential Wisconsin opinion that has
even mentioned Preston: Westphal v. Smelser, 756 N.W.2d 809, 2008 WL
2609698, at *6 (Wis. App. 2008) (citing Preston for the unremarkable prop-
osition that employment at will qualifies as a contractual relationship).
Also, if Wesbrook believed that Wisconsin courts might disapprove Pres-
ton if squarely presented with the question, he could have filed his com-
plaint in state court. If he had done so, the defendants could not have re-
moved the case to federal court because three of them were Wisconsin cit-
izens when the suit was filed. See 28 U.S.C. § 1441(b)(2). Cf. Stamp v. In-
surance Co. of North America, 908 F.2d 1375, 1379 (7th Cir. 1990) (“We are
not sympathetic to plaintiffs who opt for a federal forum, lose, and then
want a second opinion from a state court.”).
20                                                    No. 15-3870

a federal court’s interpretation of state law. See, e.g., United
National Ins. Co. v. DePrizio, 705 N.E.2d 455 (Ind. 1999) (disa-
greeing with Seventh Circuit prediction of Indiana law on
whether umbrella liability coverage limits applied to under-
insured motorist coverage); Morris B. Chapman & Assocs., Ltd.
v. Kitzman, 739 N.E.2d 1263, 1272 (Ill. 2000) (disagreeing with
Seventh Circuit prediction that Illinois common fund doctrine
applies only in class actions and insurance subrogation cases).
Absent signals from the state courts or other developments
that call into question an earlier Erie Railroad prediction, the
principle of stare decisis controls. See Midlock v. Apple Vaca-
tions West, Inc., 406 F.3d 453, 457 (7th Cir. 2005) (discussing the
principle).
    Second, we think Preston was decided correctly. If Preston
had allowed the plaintiff’s tortious interference claims to pro-
ceed to trial, it would have opened a rather broad avenue un-
der tort law to bypass well-established limits on contract rem-
edies for at-will employees. Fired at-will employees who have
no remedy under contract law would have an incentive to sue
not their employers for breach of contract but their former co-
workers and supervisors in tort. Under Wesbrook’s theory, a
fired at-will employee would be entitled to a jury trial if there
were evidence of ill will or malice on the part of a former co-
worker or supervisor who participated in a firing decision.
Such evidence would not be rare. Such a new avenue under
tort law would likely “transform employment at will into em-
ployment terminable only for cause,” Preston, 397 F.3d at 543,
as the threat of personal liability in a lawsuit could easily dis-
courage supervisors from taking adverse employment ac-
tions.
No. 15-3870                                                  21

    In Wisconsin and elsewhere, there is a “strong presump-
tion that an employee contract is at will unless the terms of
the contract state otherwise.” Heinritz v. Lawrence University,
535 N.W.2d 81, 83 (Wis. App. 1995). While the policy choices
reflected in the doctrine of at-will employment are open to
debate, the choice of those policies is a matter of state law to
be decided by state legislatures and courts. We see no sign
that Wisconsin would be inclined to open this tort detour
around roadblocks of contract law in cases like this.
   The district court correctly entered summary judgment for
the defendants. The judgment of the district court is
AFFIRMED.