Deliberate mistake: At graduation, after Troy is handed the diploma, in the overhead shot the graduates on the left and right stand-up from their seats, then turn and walk towards each other. All their seats simply disappear between shots. Obviously done deliberately for the dance sequence, but a mistake nonetheless.
Deliberate mistake: When Peter and Miraz are fighting, Peter stabs Miraz and then brings the sword back up for the killing stroke. There is no blood on the sword. This is deliberate on the part of Disney, so as not to show blood, but a mistake nonetheless.
Deliberate mistake: There are several large security mistakes that were obviously added to the film to move the plot forward. The takeover of "Control" would not happen that way. The Secret Service keeps it in a secret off site location which not even the security detail knows. This location is in some kind of very remote bunker to prevent what happens in the movie. Secondly, when the threat is identified and the switch to the double is made, the President would have been moved to a secure bunker created for the purpose until the threat was dealt with.
Deliberate mistake: When Max and 99 are in the air, they can be seen talking to each other. This is not possible (as proven on Mythbusters) even if you were yelling at the top of your lungs. The wind would make any noise unrecognizable, yet we hear them talking to each other just fine.
Deliberate mistake: The priest that Ray kills doesn't stagger out of the confessional booth toward the little boy until he's already been shot twice, yet when Ray sees the boy he accidentally shot, he is still kneeling in the prayer position and therefore did not move or react whatsoever to the first few gunshots only a few feet away.
Deliberate mistake: It is shown throughout the film that card keys are to be used to open the hotel room doors; this is a security measure that is used for doors in elegant and expensive hotels (if not all). There are no hotels that use this measure without having break-safe metal material inside of these doors, yet the killer and cops are shown breaking down doors fairly easily. Add to this the fact that only thin slices of wood are shown breaking off of the doors, not metal nor even the card-keying device.
Deliberate mistake: When Penny is loaded onto the ambulance at the end, her gurney is rolled straight in. This is wrong, the paramedics will collapse the wheels and slide the gurney into locks to hold it still during the drive. It was done this way since Mittens and Rhino were hiding in the collapsible section.
Deliberate mistake: When the red jeep is driven into the tree, two of the occupants are thrown through the windscreen with such force that they land about 15 feet away from the vehicle, one of whom was sitting in the back. But John, who was in the front passenger seat with no seat belt on stays put. Then calmly gets out seemingly uninjured? (00:32:30)
Deliberate mistake: Director Adam McKay states on the commentary that they went to the island Catalina for location searches and realised that he did not really like the island. Instead, on the coast and during several scenes, the island of Catalina can be seen in the background. He chose not to have it digitally edited out as a joke.
Deliberate mistake: When the Dragon Emperor is giving his Terracotta army the speech near the end, you see a shot that pans across the faces of several of his soldiers. A few shots later, this exact same shot is played in reverse. It is very easy to tell if you look at the way the camera moves up and down to catch the different faces.
Deliberate mistake: The helicopter camera shot of buildings under construction in Dubai plays backwards, to achieve a better effect. It's given away by the traffic on the ground traveling backwards, trucks make this particularly obvious.
Deliberate mistake: When Zohan and Phantom are seen on the Palestine beach competing about which one is the tougher, they let themselves get bitten by a piranha to prove their point. While piranha are by legend very vicious fish, its presence here is a two-fold mistake, for a) piranhas are found in South America, and b) they are fresh water fish. (I know that this is for pure humour, but the writers should have picked a rabid crab or something; that would be more appropriate for the setting.).
Deliberate mistake: When Seth Green and Lance pull up to Ian and Felicia, the car being pulled by the carriage should roll a little bit after the carriage stops moving, but instead it stops on a dime when it is only being pulled by rope, and nothing else to stop it with when the carriage stops. (00:42:00)
Deliberate mistake: When Ami's school friend is killed, a short sword is stabbed into the top of her head. Less than a half-second later, we see her face is totally coated in blood, and she gurgles even more blood before dying. There simply has not been enough time for such a volume of blood to have dripped down her face.
Deliberate mistake: Wyatt is killed in a park next to El Prado museum (which can be seen in the background). Then S and McQuarry cross the street and appear next to where the bank was. This speeds the pace of the movie, but truth is that the building of the bank and El Prado are 20 minutes walking distance away from each other.
Deliberate mistake: In the final fight, two master Brazil Jujitsu fighters, one an instructor and the other a champion, execute rear naked chokes without the requisite body locks, using the legs to control the body. In the first case, Mike was able to escape the choke by flipping backwards, which a body lock prevents. In the second case, Mike was able to strangle Silva even though any trained fighter could prevent it by simply twisting their body. (01:30:00)