Continuity mistake: Gimli is lying with his face under the water, after jumping off the Deeping Wall and landing on the Uruk-hai. In the close-up, the right arm that grabs Gimli's shoulder to help him out of the water is Legolas' right arm. Yet, in the wide shot, suddenly it is Aragorn helping Gimli to his feet, not Legolas. (01:11:10)
Continuity mistake: Throughout the entire film the tattoo on George Clooney's neck moves position and changes shape.
Other mistake: When Ace rescues the dog and replaces it with a toy dog, the toy dog is in an impossible position. Ace had to place it there when the door was still open, but if the door was closed after that the man would have knocked it over. (00:03:25)
Factual error: While Bridger is watching the film of the Mafia boss following Beckerman he signals for the film to be stopped so he can look at the close up shot of the man. He is watching a 16mm film shown through a bog standard projector - stop a film like that for more than two seconds without closing down the projector shutter (this doesn't happen - if it did the screen would darken instantly) and it will melt and catch fire. This doesn't happen.
Factual error: At the very end of the film Bruce is reporting on a drive for blood donors, and Grace leads him over to the booth to give blood himself - he is even wearing a tourniquet. However, he is supporting himself on a walking stick - he is not fully recovered from the injuries he received when he was run over, which happened when he was hit by a moving car - injuries which left him clinically dead. There is absolutely no way that a person who has suffered life threatening injuries and has undergone the (inevitably) intensive drug therapies and surgical procedures involved while under treatment in hospital in the fairly recent past would be allowed to give blood. There is no way that the Red Cross (or the US equivalent) would want to encourage people who have recently been hospitalised to try to give blood. Not only would that be the height of irresponsibility, they would be wasting precious resources and staff time turning away people who would not be allowed to give blood.
Factual error: Trevor - a Professor of Geology - boasts about having an article published in Scientific American, and that is not something any scientist would do. Scientific American is looked upon with slight disdain by the scientific community, considered to be a populist crowd pleaser. It is not even peer reviewed. Considering that he has just turned the geological and archaeological worlds on their heads he would have been better off publishing in Journal of Geological Research or Geology, both prestigious professional journals.
Revealing mistake: In one shot when the boat is pulling away from the waterfall, you can clearly see that the shot is the same one they used earlier in the movie. The water from the waterfall now is going up the cliff! They have just put it in reverse.
Continuity mistake: Towards the end of the movie, when Joey Nova is trying to get out of town, he sells his football ring to the drug dealer, but in the final scene he is clearly shown wearing the ring when he points the gun at his father.
Visible crew/equipment: When Dr. Okun is about to unlock "the vault", and says, "The freak show," a crewmember wearing a black and white striped shirt is hiding under the vault's floor, right behind Okun. (Only visible on fullscreen DVD.)
Visible crew/equipment: When Pee Wee is chaining up his beloved bike you can see the long chain coming up through the bottom of the bike box. Full screen version only. (00:13:40)
Factual error: During CONTROL's paintball training session, a barrel view of a bullet exiting the gun is shown as it travels to its target. However, the entire bullet is shown, casing and all, instead of just the bullet. (00:09:10)
Revealing mistake: When the leading hitman jumps from the balcony you see him land on a rubber mat.
Continuity mistake: In the exterior front shots of Elliott's house there are some significant changes to the landscape in different shots. For instance, the two lampposts at the bottom of the driveway change to an entirely different style in some shots, and the huge garden boulders repeatedly vanish and reappear. Also, note when Michael takes off on Elliott's bike to go search for ET, the in-ground lamppost that should be beside the mailbox has vanished, but it reappears when all the government agents are setting things up outside the house.
Other mistake: When Adam comes in and says "when I woke up this morning, the pain was gone", Connie is mouthing his lines behind him.
Continuity mistake: When Tim and Lex first arrive, Lex is wearing a purple tank top with a colorful design, and in the following scenes or even between consecutive shots her tank top changes to completely different designs, though it's the same style of tank top.
Continuity mistake: After Mark is found, he runs into Kate's arms and hugs her and her sunglasses fall off her head, but then in the very next shot they're back on her head perfectly. (01:24:50)
Continuity mistake: In the first film, it is mentioned several times that Kevin is 8 years old. However, in this film it is stated that he is 10. When his parents are in the Miami airport security office, they say that he was left alone last Christmas. That would make him 9. Both films take place the same days, from about three days before Christmas until Christmas morning, so even if Kevin is born around Christmas time this is still a mistake.
Continuity mistake: The tyres on the crotch rocket motorcycles they were riding kept changing from knobbly tyres to road slicks, back and forth depending on what terrain they were on. Easiest to see when Ethan skids on the road to avoid the white van - clear shot of slick tyres - then about 30 seconds later they're on the dirt, he skids into the old car and you can easily see that he's got off-road tyres front and back.
Character mistake: Jim Sturgess uses a sentence that contains the word 'me'. He is corrected, being told that the word 'I' would have been correct. However, he was grammatically correct in his use of the word 'me'. The correction was in error.
Continuity mistake: If you look carefully at the monster (Frankenstein) you will see that his face is different in the ending scenes. The reason is, during the movie you see the monster take the woman doctor and throw her out the laboratory window. You then see the monster kind of stumble, which he really did and broke his ankle. So in the final scenes they replaced Lon Chaney Jr. as wolfman with a stuntman, and Lon Chaney Jr. finished the movie as the monster.