Revealing mistake: When Daniel is being chased along the rail tracks, both the Peugeot and the Mitsubishis' wheels change from road wheels to train wheels (with fake tyres on) and then back again when they move back onto the gravel. Clever cars... (01:11:05)
Revealing mistake: About a minute into the movie we see Ethan Hawke waking up. He has a tattoo on his left pectoral. He then goes to the sink and mirror and the camera is directly behind him. He drops out of shot and in the same shot reappears in "the reflection" as he splashes his face with water. His tattoo is still on his left pectoral - all he's done is drop out of shot, move forward a few paces, turns around towards the camera and reappear as the mirror reflection. They've forgotten to either flip the image around or put the tattoo on the other side. (00:06:00)
Revealing mistake: There is a large cut on the glass window prior to Liotta smashing it, to make it easier to break. The scratch was not there in the previous shots of them leaving the car. (01:03:05 - 01:28:50)
Revealing mistake: When Dekker follows Richards on a motorbike he drives through a glass door with wooden frame. The class shatters noticeably (about a half second) before the bike even touches the door.
Revealing mistake: When Les' mom is doing the laundry and "finds" the Test Failed notice, you can see that she actually had it in her hands the entire time. She transfers it from one hand into the other, then puts the hand with the paper into the pocket and pulls it right back out, then knocks it off onto the floor, and acts surprised.
Revealing mistake: When Hightower throws his frisbee to Proctor and sends him flying, Proctor starts flying away before he catches the frisbee.
Revealing mistake: When Tee Hee bends the barrel of Bond's Walther PPK, in the close-up, the score marks where the barrel has been pre-cut are visible.
Revealing mistake: The boulder, which comes rolling down the hill in the beginning of the film, is a fake. Fair enough, it would be too dangerous using a real one. A real one, however, would not bounce off the water of the pool as briefly can be seen.
Revealing mistake: Near the end when Gregory is threatening to cut out Ricky's eye with the sharp cutting knife, look at the tip. It's rounded so it doesn't cut Ricky while it's pressed into his socket. An experienced man like Gregory would never leave it that dull.
Revealing mistake: When Maturette dies at the end he cannot close his left eye all the way because of the totally noticeable fake contact lens he is wearing.
Revealing mistake: During the car smuggling scene where Van Damme is fighting on the boat one of the thugs slides/falls against the side of one of the cars. If you look closely, you can see the side view mirror on the car is made of rubber.
Revealing mistake: In the scene where Edward Burns, Paul Giamatti and Brian Van Holt are at Big Al's house, Big Al is dead in his chair with his eyes open. As Edward Burns walks in front of him, Big Al blinks his eyes.
Revealing mistake: In the big speedboat scene near the end, when Cage is hanging off the side of the boat the stunt double is obvious in wide shots, where the entire boat is visible from above. He has big long sideburns, which are in stark contrast to Cage's short hair, visible in closer shots. At various other points in the movie, stunt doubles appear of much different physical builds than the two actors, with markedly different hair colours, and I seem to recall that at least one of them had facial hair.
Revealing mistake: In the barber shop scene at the end of the film, Agent Anderson terrorises Deputy Sheriff Pell (who has a full head of hair) with a razor blade. Anderson throws him across the room, but the person being thrown across the room has a mostly bald head.
Revealing mistake: When Edward Norton takes Charlize Theron out to dinner, the mustache on the right side of his mouth is further away from his lip, than on the left side of his mouth showing that the mustache is only stuck on.
Revealing mistake: In the beginning right before the opening dance number begins, Gwyneth Paltrow and Steven Spielberg (in cameo roles) do back flips. You can see the stunt double doing them as the stunt double was wearing a blond wig (depicting Paltrow) that falls off after the first flip. (00:04:22)
Revealing mistake: When Atticus kills the mad dog, you can see its hind legs being pulled by someone off screen. (00:43:05)
Revealing mistake: Hamlet is killed and in the next scene is being carried with his arms stiff to his sides. The men carrying him go over a bump, jolting Hamlet, and he blinks.
Revealing mistake: Forest Whitaker has been running after the secret service agents for a while, but when he stops to film the cop getting shot, he isn't remotely out of breath.
Revealing mistake: During the driving scene, the background is illuminated by non-existent headlights. It's running backward on the projection screen.