Whistleblower (The Office) fourth appearance on the show, after first appearing in "Sabre". Zach Woods made his ninth appearance on the show. While talking with his real estate agent on his cellphone, Dwight states that the office park is 1725 Slough Avenue. "Slough" is a reference to the UK edition of "The Office" which is set in Slough, United Kingdom. In its original American broadcast, "Whistleblower" was viewed by an estimated 6.60 million viewers with a 3.4 rating/10% share in the 18–49 demographic coming second in its timeslot after the season finale of "Grey's Anatomy", receiving the same rating as last week's episode,
The Duel (The Office) the exterior shots because the writers were trying to simulate the winter season weather of Scranton, Pennsylvania, where "The Office" is set, rather than the Van Nuys district in Los Angeles, California, where the show is filmed. The original script called for Michael to tell Andy about Angela's affair outside in the parking lot before getting into his car and driving away. When filming began, Holland considered filming the scene inside the car instead. Steve Carell suggested Michael get in the car and leave Andy outside, then tell him while driving away, which was how the scene was ultimately shot.