Continuity mistake: In the bedroom scene the girl is holding a clear cup full of beer. The camera goes off her and when it comes back she is holding a blue cup. The camera goes back off her then on her and the cup is clear again. [This mistake does not appear in the unrated version - the blue cup scenes were shot specifically to secure an R rating from the MPAA because the contents are obscured.]. (00:13:20)
Revealing mistake: During the bedroom scene with Felicity and Fat Bastard you can clearly see the air hose that fills his suit when he rolls over in the bed. (00:49:10)
Audio problem: When Commander Taggert (Tim Allen) and Lt. Madison (Sigourney Weaver) first see the hallway with the chompers, she says, "Oh, screw that!" but if you watch her lips she clearly uses the 'f' word instead of 'screw'.
Factual error: The whole Bowfinger scenario is impossible. They are using a 35mm Panavision cine camera which cannot be focused through the lens; it needs precise measurements on the set in order to be properly in register. Then there are the light readings required to ensure proper exposure. Wouldn't Kit Ramsay notice the man with the light meter, or the one with the tape recorder? Both measurements would have to be done with him or an identically dressed and made up stand-in (a "lighting double") on the spot. Then there is the sound. Any sound recordist worth his salary will have the microphone within centimetres of his subject, and he'll have a boom operator keeping in there. We don't even see a microphone in use! Please don't tell me this is based on the clandestine filming of Mary Pickford during her Russian visit: that was done with old black and white film which has very wide tolerance to exposure and most of all it was silent, and she was aware of the camera crew, she just thought they were news crews. (And the results were rubbish anyway).
Other mistake: In the scene where the kids are shooting arrows and the coach gets hit by one, they send a girl to call 911. If you look closely and follow her in the background, after she runs a few yards, she slows down and eventually stops and stands there playing with her hair. Talk about help... (00:57:05)
Other mistake: In the beginning of the movie, when you first see Mary-Kate (aka Mel) and Ashley (aka Ally), Mary-Kate walks off without ever closing her locker.
Factual error: In the montage sequence showing Drew Barrymore hanging out with the math club, they have a Pi poster with 3.1457869986. Only the first 3 digits are actually correct. (Pi = 3.1415926535897...) (00:25:20)
Continuity mistake: During the first scene set in a prison cell, as Martin Luxford (played by Hugo Speer) is about to be released, there is a glitter ball made from an orange covered in tin foil. It is rotating first one way and then the other, as it has been spun by hand. As the film action cuts between the two characters, the ball mysteriously changes direction without having slowed down and at one point appears stopped, having previously been rotating rather fast.
Revealing mistake: When Claude and Ray are at the retirement home getting ready for bed, as Ray lifts up his shirt you will see where it looks like he's wearing a fat suit underneath. He can also be seen pulling it down to his waist.
Other mistake: When Catherine breaks into Crown's house, her assistants immediately get to work on the security panel. When the first assistant touches the panel, it falls off the wall and he has to quickly push it back into place.
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.
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.
Continuity mistake: Luca and his friend are chasing a bus and come down an old dirt road, Luca in a side car with a dog in his lap. The next shot, there's no dog, then the next shot the dog is back in his arms again.
Continuity mistake: When the Mystery Men smash their "Magnetic" Herkimer bus through Casanova's Castle's main gate you can see a number of the lights mounted to the front of the bus are smashed, however, in the next couple of front on shots, you can see that all lights are working and intact.
Continuity mistake: In the scene where Jonathan picks up the scarab, it breaks open and the beetle inside starts to crawl under his skin. We see Brendan Fraser tear Jonathan's shirt and cut the beetle out of him. However, in the very next scene, we see Jonathan walking into the temple, his shirt is intact and there is no blood to be seen. (01:37:05 - 01:38:30)
Continuity mistake: Every time they show the outside of the bookstore, on the left you see the same adult drying a child's tears. (00:17:55)
Continuity mistake: When Sly is in the attic, and the fake power dude comes up to kidnap him, Sly uses a ski to "hit him in the gonads". But if you look closely at his face, the guy who was hit in the nuts wasn't the same guy that fell down the stairs.
Other mistake: When the switch is thrown to electrocute Terrence and Phillip, it's pulled downwards. A few shots later, we see Cartman jump in to save T and P by turning the switch off. He also pulls the switch downwards instead of pushing it upwards. (01:06:05)
Continuity mistake: After becoming fed up with his Luke Wilson's slow driving, Lawrence decides to take over. When he jumps the bridge, they cut to the reactions of the actors inside the car. You can see in the background that they are not airborne, but still on the ground.
Factual error: It is said in the film that Ice Cube's character works in an airport in Detroit. When the scene shows Ice Cube at work as a baggage handler, there are mountains in the background. There are no mountains in the Detroit area. (00:14:10)