Revealing mistake: When the group is leaving the dinner they are talking while standing outside in the snow. It is supposed to be in COLD Wisconsin, yet you cannot see anyone's breath as you would when someone is talking outside in the cold. (01:15:50)
Factual error: If you're a Hertz #1 Club Gold Member like Ryan is, you don't need to swipe your card or sign for a rental as shown in 2 scenes. You just go to your assigned car in the lot and show your driver's license at the exit.
Visible crew/equipment: When Alex closes the door of her home, huge squared lighting screens get reflected on the glass window on it.
Factual error: When Bingman is shown leaving Detroit, he is in front of a large window with a 747 outside (also the movie cover). This fountain and location is inside the McNamara terminal in Detroit. As he is a million miler with American Airlines, he would be in the other terminal.
Factual error: In the first scene that takes place in Ryan Bingham's office in Omaha, if you look out the window, a City of Saint Louis, Missouri flag (red with a blue sort of sideways Y shape on it) can be seen in the reflection of the building across the street.
Other mistake: When Ryan and Alex are first together in the hotel room, there is a gratuitous nude view of her getting on the bed. The body double used for this couldn't be more than 21, and her appearance is quite at odds with the character, who is pushing 40.
Suggested correction: This is pure opinion. Yes, it has been said that a body double was used in this scene. But within the world of the movie, there's no reason that can't be Alex. She reveals later that she's 34, and many women look absolutely splendid at that age. We see her partially nude in the very next shot, with no big discrepancy from what we saw from behind. It wasn't until after several viewings of this movie that I found out that this was a double, and even now that I know, it's still not obvious at all.
Factual error: When Bateman orders Clooney and Kendrick to return to Omaha from Detroit, there is a shot of them waiting in the McNamara Terminal. This Terminal, however, only holds Northwest/Delta flights. They would be in new North Terminal of Detroit Metro Airport, since they fly American Airlines.
Factual error: After the rehearsal dinner, Ryan is told to turn up around 5pm for the wedding to start at 5.30pm. In February, sunset is between 5.04pm and 5.42pm for Waupaca, so it would be dark outside, however, when the wedding takes place and into the dinner itself, it is light outside.
Continuity mistake: In the scene where Ryan and Alex are comparing travel cards, Alex's grip on Ryan's concierge card changes in close-ups.
Factual error: In the scene where Bingman leaves Chicago after visiting Alex, he is shown riding the airport tram. This tram is inside the McNamara terminal in Detroit.
Other mistake: In the scene where Ryan Bingham is giving his self-help presentation to an audience in Miami, he is standing behind a podium that says Wichita.
