Continuity mistake: When Ben Stiller goes to the girl's house in the white suit - she slams his head into the wall and a blood/makeup stain shows up...when the camera angle changes the stain is gone. (00:42:05)
Continuity mistake: During the final game when Justin is by himself, you can see Owen sitting on the bench without his track suit. When he throws the ball at White you can quickly see in the background Owen is standing behind Justin with his track suit on. Few shots later it cuts back to the bench and he is sitting down with the rest of the team with the uniform minus the track suit. (01:16:23 - 01:16:30)
Continuity mistake: When the guys are all sitting around (after the car wash) they are throwing ideas to save the gym. In one shot Gordon pulls his magazine out of his bag, but a split second later in a closer shot he pulls the magazine out again. (00:15:15)
Continuity mistake: When Peter first leaves his house near the beginning of the movie, he throws his empty bottle at a lawn chair, and it bounces off onto the ground. In the next shot, when he drives away, you can see nothing on the ground and what looks like the bottle now lying on the chair. (00:03:20)
Continuity mistake: When Martha Johnstone falls on Justin during the cheerleading tryouts, her skirt falls up and is laying on her back; they show this in a front view; but when they switch to a side view, her skirt is back down covering her bottom. (00:06:35)
Continuity mistake: When White is sitting down with Kate at her house, he shows her the red flower he picked from her garden. The first time, the flower looks crumpled and a bit damaged, from the other angle it is perfectly fine. (00:41:00)
Continuity mistake: When the Average Joes wins the tournament, fans rush the court as well as the cheerleaders and bondage people. The very next shot the cheer squad and bondage folks are in the stands. (01:22:30 - 01:22:35)
Continuity mistake: When Peter opens the door to his file closet to show Kate his paper work, the door on the left changes from being open wide to just slightly open throughout the scene. (00:09:40 - 00:09:43)
Continuity mistake: In the scene when Gordon gets angry seeing his "mail order wife" with another man you can see the dancers in the background, behind Gordon, just standing around. When the camera pans out they are all dancing and celebrating. When it cuts back to Gordon they are just standing and leaning against the pole. (00:58:00 - 00:58:55)
Continuity mistake: When Justin is trying to rally all the boys behind saving Average Joe's, he throws a blue icepack on the couch when he stands up. When it focuses back on Gordon, the icepack is gone. When they show Gordon again, the icepack is back. (00:13:15 - 00:13:50)
Continuity mistake: When Average Joe's team are running to the balls against Skillz That Kill, you see the Lumberjack's feet instead. (00:53:55)
Continuity mistake: After White knocks the food onto the Average Joe's players in the bar, Owen is holding a martini glass in his left hand. The following shot, the martini glass has disappeared. (00:32:35)
Continuity mistake: When Peter is talking to White about the deal, Me'Shell is standing in back of Peter. In the first two shots his hands are on his hips, in the third shot his left hand is over his right wrist on his stomach, and the next shot his hands are on his hips again. (01:01:05)
Continuity mistake: When Michelle takes the screen prints of Kate throwing the dodgeball at his cutout, the screen capture on the monitor differs from what he shows to Goodman at his office. The shot is flipped over and from a different angle. (00:40:05 - 00:41:20)
Continuity mistake: When Gordon is talking to Peter about the OSQ magazine about midget tossing, right before Gordon hands him the magazine, Peter has an orange juice carton in his hand. In the next shot you see him holding the magazine with both hands empty, with not enough time to get rid of the orange juice. (00:04:40)
Continuity mistake: In the first scene that Vince Vaughn goes to global gym to confront Goodman, Vince and Ben are talking to each other. During the conversation, you can see a woman working out on a fitness machine behind Vince. When the shot widens as they are leaving, neither the machine nor the woman is there. (00:10:50)
Continuity mistake: In the final showdown after Peter knocks White down, his team rushes on to congratulate him. At first the court is clear behind Peter, but when the team rushes on there are a lot of balls behind him. In the same scene, there is a large, black box with skulls and crossed bones on it that isn't seen in the wide shot. (01:19:30)
Continuity mistake: When the waitress gets pushed into the table at the Dirty Sanchez, the food splatters everywhere, but none of it gets on Owen; he is completely clean. Then, they have a shot of him directly afterward, and he is completely covered in food. (00:32:35)
Continuity mistake: In the first shot at the car wash, there is a white car parked beyond the lifted truck, in the background. In the very next shot that car is gone. The dog also goes from lying down to instantly sitting up, between the two shots. (00:14:30)
Continuity mistake: When Peter meets Lance Armstrong and they are talking, Lance has a bottle of water in his hand. As the camera keeps changing shots from Peter to Lance, the bottle of water changes back and forth from having a cap on it to not having a cap on it. There's no time for Lance to have taken it off and put it on that many times. (01:10:35)
Answer: There were many celebrity cameos throughout the film. It's just kind of strange that Chuck Norris would do this.