Revealing mistake: When Nick has swam back to his water scooter, he climbs up and drives away and the shark comes up behind him. But look carefully behind Nick as he is climbing. The nose of the shark is visible during the whole scene, right under the surface. This proves that the shark was a dummy, waiting to come up.
Revealing mistake: In the first morgue scene the body on the table is obviously breathing.
Revealing mistake: When the shark is on the deck of the Andrea Gail, you can see the equipment underneath it that is making it move. (00:47:30)
Revealing mistake: During the war flashback there is a newspaper photograph with Captain Junuh on the shoulders of Savannah's young men. When the camera zooms into his face you can see it's someone else's, only in close-up it switches to Matt Damon's. This is surprising because in all other newspaper pictures Matt Damon is nicely worked in. (00:06:15)
Revealing mistake: In the first few shots of Cheryl having sex with Leon you can see she has strips of white tape on her chest discreetly covering her.
Revealing mistake: In the fight scene between Riddick and Johns, there is a wide shot of them both fighting over Johns' shotgun. In this shot it is apparent that it is not Vin Diesel in the shot but in fact a stunt double. (01:17:35)
Revealing mistake: When one of the civil cops knocks at Jimmy's door it is obvious that someone behind it (from the movie crew) opens it. He doesn't knock hard enough to make the door slide open by itself. (01:47:45)
Revealing mistake: Trevor Stark appears as the twin brother of Travis. They both have the same scar on their left cheek. Therefore they are the same person and not twins.
Revealing mistake: When the guy with the hand missing is playing his guitar, you can see his actual wrist bending underneath the fake arm that covers it.
Revealing mistake: In an early shot shown from the neighbor's house, it is established that the Spencers' house is quite a ways uphill. Some of the later shots where Claire is spying on her neighbors and looking at their home, the angle of view does not appear to be correct. The neighbors' house looks like it's a lot closer and more level with the Spencers' home.
Revealing mistake: When the killer is in the shower, he is supposedly nude, however one can see his flesh colored thong he is wearing for modesty.
Revealing mistake: When the "dudes" are taking out a load of bin bags, you can see through the lighter coloured ones that they are actually filled with polystyrene chips (the packing kind) rather than any litter.
Revealing mistake: When Deebo is getting attacked by Joker's dog, you can see protective padding on his arm.
Revealing mistake: In the end, when Paula kills Hein, you can see in close-ups that the scars on his face are on tape and not on his skin.
Revealing mistake: When Alex drops the cigarette lighter to ignite the gas, you can see the flame is started from a different source, as it starts on the other side of the screen, a fair distance away from where the lighter landed.
Revealing mistake: Fireproof gloves appear on the slave turning the wheel when he's burnt by the dragon.
Revealing mistake: In the bowling alley scene where Jeremy and Nick are discussing the red-haired woman, you can see Nick shaking from laughter and even hear it. It is easier to spot if you have watched the outtakes. Nick simply could not contain his laughter during this scene and so they just shot him from behind and left it in. This happens in another scene as well, when they first enter Jeremy's "manly" den. These two were just having too much fun filming this movie. Watch the outtakes.
Revealing mistake: When the group of journalists is heading to Vukovar, they are stopped and go to hide because fighters are bombing the town. At one point, the camera moves and the airplane moves with it.
Revealing mistake: When Sarah and Gretchen share the shower with Sebastian, you can see flesh-coloured underwear on their hips, to protect their modesty. (00:35:00)
Revealing mistake: All of the earthquake scenes are badly staged (since they were accomplished by the very low-budget technique of shaking the camera). Nothing except the actors ever falls down save for the occasional large object to grab your attention. This is most obvious in the scene at Saffron Burrows's home, as there are many things that should have been knocked over (lamps, vases, etc.) which are still standing upright despite many large shocks that have already occurred.