Revealing mistake: When Peter Parker first discovers he can climb up walls (while in citizen clothing), he tests it out by climbing up a building in an alley. During this scene, you can clearly see his clothes hanging out forwards, indicating that the scene was filmed with him crawling along a floor horizontally. (00:24:50)
Revealing mistake: At the end when Sullivan is shot in the back while looking out the window, you can see blood come through the front of his shirt, meaning the bullets must have exited his body, yet the window he is standing in front of isn't shattered by the bullets that had passed through him. Also, immediately after this when Jude Law sets up his camera to take photos of Tom Hanks dying, the blood all over the glass is completely gone. The window is clean.
Revealing mistake: On the transport trailer, Frank leans out his car window and dramatically fires at the ramp's tall lever control in a close-up, located at the rear of the transport over the tires. The problem is that the trailer has no such lever control, as seen in the previous shot before it drives under the bridge overpass. (00:07:55)
Revealing mistake: In the scene where Norton's wife is target shooting with the revolver, there aren't any bullet heads showing in the cylinder. There's also no recoil as she fires.
Revealing mistake: At the party someone asks Marcus his name and he replies 'Vincent' the actor's real name (Vincent Cassel).
Revealing mistake: The scene where Amsterdam and Jenny are in the room together above the tavern, shortly after Bill's assassination attempt, Amsterdam pushes Jenny up against a 12 inch by 12 inch wooden beam. The problem is when he is pushing her up against this beam, you can see it flexing with the weight. Then Amsterdam is holding the beam, you can see that the beam is some type of cloth because the slight touch of his hand makes it dent in. (01:20:45)
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: 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: 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: At the end when Li'l Zé (Zé Pequeno) and his crew want Rocket (Buscapé) to take a picture of them in the street, a long-haired boy with a blue shirt is the first to be killed in the final shooting. A couple of seconds before he is shot in the chest, the shape of the blood pack is visible under his shirt.
Revealing mistake: When Clint Eastwood and detective Jay Winston are talking in her office she walks over to the blinds and touches the plastic piece that closes them but nothing happens, they stay the way they were. She does this twice. (00:25:46)
Revealing mistake: When the two main characters explode and then implode near the end, you can see that some of the debris being sucked in are passing "through" various other objects, revealing they are computer generated.
Revealing mistake: When Tommy and her boys are roughing up Randolph in Angie's apartment, Tommy throws Randolph across the room into the piano. The vase sitting on top of the piano falls before Randolph ever touches the piano. Seen better in slow-mo. (00:57:20)
Revealing mistake: About 30min into the movie, there is a scene at an airport with a 4-engined 707 freighter. As the characters walk behind the jet, you can see that the left-hand inboard engine pod has no engine on it, unlike the outboard pod. The aircraft is obviously being dismantled despite the appearance of having just landed.
Revealing mistake: When Kevin Bacon is talking to Courtney Love on their cell phone and he hangs up on her, a dial tone can be heard on Courtney Love's phone.
Revealing mistake: In the shot where Sandra Bullock revisits the site where she was dumped years ago, you see her car pull up on what is supposed to be a moonlit road. As she gets out of her car, her shadow goes from left to right across the screen but the large tree on the left is casting a shadow in the opposite direction. As she passes the front of her car, no shadow is cast from the headlights and when she reaches the edge of the road, her shadow disappears completely. (00:21:25)
Revealing mistake: When Anderton first sees himself killing Leo Crow in the precog vision, pay attention to the shot when he says "no". The reflection of Jad in the Hi Tech screen doesn't match with his movements.
Revealing mistake: Terry gets drugged. A needle in the neck. Yet she is able to run over to Mike like the drug had no effect on her.
Revealing mistake: If you look closely at Billy Flynn in the musical number "All I Care About is Love", right at the end when he takes off the boxers, you can see that he is wearing underwear underneath them.
Revealing mistake: In the Atlanta party scene, we are supposed to believe it starts with a single long take. However there is a sneaky edit when Frank crosses the threshold of the room. He emerges at a slighty quicker pace and his hair is suddenly messed up. (01:10:35)
Suggested correction: There is nothing obvious in this scene that supports this. When he emerges on the other side, he bumps into his friend so suddenly that you can't tell if he was walking at a different pace. The reason his hair is messed up is because he bumps into his friend. He then yells at his friend, jerking his head around as he does so, which messes up his hair even further, which can be seen.
Even if it were true, it wouldn't qualify as a mistake. The shot may be intended to appear as a single shot, but that doesn't mean it's a mistake if it isn't.