Continuity mistake: In the scene near the end of the movie where Peter apologizes to Joanna, Joanna is shown either in her red shirt and holding her blue jacket, or wearing her blue jacket. For instance, as Joanna is moving in to kiss Peter, she is holding the jacket, but as they embrace, she is wearing it. In the blue jacket cuts, it is much less windy, and Joanna's hair is styled differently than it is in the red shirt cuts, where her hair is blowing due to the wind.
Continuity mistake: During Tom's BBQ when Michael Bolton and Samir are asking Tom's lawyer about prison you see Michael lose grip and drop his cup with a piece of ice hitting Samir in the head. When the ice hits him he's holding the cup in his left hand but when the camera angle changes the cup shows up in his right hand.
Continuity mistake: When Peter goes to see the Bobs for the first time, he comes in, there's the Bobs sitting on the right side of the desk, and the row of empty chairs on the left. One of the chairs is not pushed in and turned left but when Peter comes back to sit down after getting his water it is pushed in and straight.
Continuity mistake: In the restaurant scene the volume of the water in the glass in front of Jennifer Aniston continually changes from full to half-full depending upon whether Aniston or Livingston is talking.
Continuity mistake: When Peter is shutting his computer down to try to escape his boss, one of the cuts shows that it's an OptiPlex monitor (us computer people will recognise this), then they cut back to Peter, back to the monitor and there's a piece of black electrical tape covering up the company logo on a completely different monitor.
Continuity mistake: In the scene where Lumbergh is talking to Milton in the building basement, his ever-present cup of coffee switches hands between shots.
Continuity mistake: When Lumburgh meets with the Bobs, Dom is sitting beside him during the entire meeting. However when Bob Slydell pulls Lumburgh's personnel file, Dom has disappeared from the room.
Factual error: Following on the previously submitted mistake about the MacOS and the C: prompt, when Michael is loading the penny-fraction program he is using a Mac but his hand is on a two-button mouse, which Macs don't have.
Continuity mistake: When Lumbergh is talking to Milton in the basement, he is finishing his piece of birthday cake. He throws the plate out in a nearby garbage can, then suddenly has a cup of coffee in his hand, when Dom comes running after him.
Continuity mistake: When Michael gets pulled away from beating the copier, he has a cord in his hand which he drops before going back. They pull him away again and the cord is gone, but in the last shot it in his hand again.
Continuity mistake: When the guys go to Flinger's for coffee, we see that the little cardboard triangle thing in the middle of the table advertising new additions to the menu (most restaurants have these) is facing the camera with 3 lines of text reading "Try our Jalapeno Poppers." In all the shots with that triangle thing in it after that, it has 5 lines of text facing the camera reading something different.
Continuity mistake: In the scene with Samir, Michael, Peter, and Tom in the office talking about Tom's 'jump to conclusions' mat, the army men in the background on Peter's cubicle change positions. Shots of Michael show the kneeling man with the bazooka on one side of the minesweeper, shots of Peter show them in reversed positions.
Continuity mistake: Towards the beginning of the movie when Peter Michael and Samir are at the diner for the first time, Peter notices Jennifer Aniston and she has two full plates of food in her hands. Then she gets into some heated argument with her boss and they cut back to Peter and the guys again and back to Jennifer but this time she doesn't have the plates.
Revealing mistake: When the guys go to see Tom at the BBQ, he has his head in a support cage. Every time he moves, and particularly when he laughs, this cage moves around and wobbles. The point of these cages is to keep the head still and in line with the spine, and are bolted into the bone itself. Therefore, not only should it be impossible for it to be moving, it would seriously hurt if it was.
Continuity mistake: In the scene where Michael and Peter are in Michael's apartment, sitting and talking, we see Michael has a blue shirt which is spot-free. Right before they cut to the scene at the bar, we see that he has 2 small stains on the upper right of his shirt.