Continuity mistake: When Sonic and Tails are fighting metal Robotnik, he shoots glue at Tail's tail. Tails says he can't fly to help Sonic, but when he gets the piece of concrete to surf across the water on you can see that his tails are not glued together.
Plot hole: Spoiler: At the end of the film we learn that the girl is the wild animal, having been saved by the same doctor. Yet at the restaurant she is wearing a bare back dress and does not have the giant X-like scar on her back, like he has or the model has, who the doctor marries at the end.
Continuity mistake: When the two brothers are frantically trying to get out of the car because the monster truck is barreling toward them (in slo-mo), you will notice that the tongue ring is missing from the one brother's tongue. Odd mistake seeing as his character is centered around the tongue ring. (01:27:05)
Revealing mistake: When Sonny is on the payphone, you can see Julian mouthing something to the guy on the payphone behind Adam. The guy is giving him instructions.
Other mistake: When the nanny comes home with the tags, they call Jewel to get hers first. Jewel has a penis.
Factual error: When the barracks are completely flooded, several of the trainees shove shower hoses down the toilets for an "unlimited supply of air" (Merlin describes it as "simple physics"). However, that old fireman's trick is a technique for surviving dense smoke, which is not under fluid pressure. In the barracks flooded 9 feet deep with water, the pressure would be so enormous that it would easily gush straight down the toilets in a powerful torrent, eliminating any "unlimited air supply."
Continuity mistake: During the detention scene, the teacher comes in and you can see there isn't anything on his rear end. As he leaves, you can see toilet paper hanging from his rear. This was because a scene never made it into the movie where the teacher's office is in the mens restroom. Also confirmed on cast commentary.
Continuity mistake: In the very last scene of the movie where Chris O'Donnell and Renee Zellweger are on the terrace taking their vows, Renee is holding a bouquet. In one shot it is a bouquet of pink flowers, then it changes to a bouquet of yellow flowers and keeps switching back and forth throughout the scene.
Plot hole: Prior to the final show, when the horsemen are performing separately at different locations in London. [Scene X] Jack is busy with his card swap trick. While others are doing their tricks too, [Scene Y] McKinney is believed to be tricked once again by his face sharing brother at another location... Dylan gets a call and then he calls everyone to wrap up and meet somewhere. [Scene Z] Jack also wraps up and leaves the place... OK. Later after the expose in final show McKinney tells the story about how Jack successfully hypnotized his brother [in the Scene Y]. How could Jack be at two different locations at the same time? He was performing somewhere else when he did hypnotism at another location and then wraps up his trick back where he started.
Continuity mistake: William H. Macy makes dinner plans with the Mayor and writes "Dinner with the Mayor" on the dry erase board in his office. He writes "Dinner w/ the Mayor" in the "Tuesday" slot. Then an intern comes in and accidentally wipes the appointment off the board with her shirt. Macy yells at her and tells her to rewrite the appointment on the board. The whole premise of the joke and pretty big part of the movie is that the intern rewrites the appointment in the wrong day, thereby causing the Hollywood people to miss dinner, enrage the Mayor and his wife and have the town turn on them. When the girl walks away however, the appointment is clearly rewritten in the correct day (Tuesday). This ruins the whole misunderstanding because although the appointment is in the wrong day later in the movie, at the moment the joke is supposed to be set in motion, there is no mistake.
Continuity mistake: A couple of scenes after the baker's wife ripped off most of Rapunzel's hair, it has grown back to full length so that the prince can climb up to the tower on it.