Revealing mistake: In the day following the Rider's first ride, Cage shows up at the street that has been burned down the center. A person very close to the beginning of that scene walks on the broken up rocks and it moves as if it were a pad or a sponge. It wasn't a rock moving because the street moves with the rock. It happens a couple of times during that scene.
Revealing mistake: When the taxi goes over the edge to capture Dr. Neville, you can see that the underbody of the car as it goes over is a flat painted surface and not the underside of what should be there (i.e., muffler, gas tank, etc.).
Revealing mistake: As Carlos is giving his final goodbyes to Claire you can see in the background automobiles driving down the freeway. Shouldn't these roads be empty rather than having what seems to be a thriving highway? (01:10:00)
Suggested correction: Not a single car in the background.
Revealing mistake: When Sandman is in the truck of sand and the cop climbs up to catch him, you can see the edge of a platform uncovered. The platform is clearly there so the cop could walk without sinking - he stops right where the platform ends.
Revealing mistake: When Blackout is destroying the base in Qatar, a few Humvees get flipped over, and none of them have engines in them. (00:07:00)
Revealing mistake: During the heavy snowstorm, the telephone wires are still, even though it's a blizzard.
Revealing mistake: In the scene at the motel where Chigurh kills three men, he goes to sit on the bed where he removes his socks. In the background one of the 'dead' men opens his eyes and looks around.
Revealing mistake: When McClane goes into the icy room in the power station, look at the pipe to the side of the acrobat: it's in shot a few seconds and you can see that the writing on the pipe is reversed, revealing that in the editing room, the shot was flipped.
Revealing mistake: In the scenes where Riley is using his computer to look up information on the "SearchInfo" site, the screenshot used is of Wikipedia. (You can even see the "About Wikipedia" link on the left).
Revealing mistake: The quick shot of the Bible landing in the drawer is reversed. (00:29:20)
Revealing mistake: During the scene where the military loses control of London, and their snipers are told "all targets are free", you can see heavy padding beneath Infected/civilian victims' shirts, etc, as they're shot. Presumably it's to stop them injuring themselves when they fall over, or to hold apparatus for the blood effects, but it's too bulky to be part of the characters' clothing.
Revealing mistake: When Conrad throws the Russian over the cliff, as the Russian explodes, you can see that poor CGI actually makes him transparent.
Revealing mistake: When the C130 is taxing on the runway (just ahead of the police search of the plane) you can see a C-17 in the background. The C-17 only made its maiden flight in 1991.
Revealing mistake: When Jack Gramm's Porsche explodes and make a flip in the air, the rear compartment where the engine is supposed to be is empty, and the rear axles and the tailpipes are common pipes.
Revealing mistake: By the end of the movie, when Jamie Foxx is holding the dying Arabian cop, you can see that Jamie's neck injury looks extremely false.
Revealing mistake: When Laura falls in the bathtub, a stunt is doing the fall, because her hair colour and style changes.
Revealing mistake: When Art is hitting the Trevor (the blinded man) character with the hammer/hatchet in the beginning, if you look closely, you can see blood coming from Trevor's head, yet there is no wound or cut. The blood is actually coming from the prop that is hitting him in the head. (00:09:00)
Revealing mistake: There are 4 different vehicles in the movie that have the same license plate number (2PCE275). The first is on a white car owned by the gang member that shoots Max. Then you see the same plate number on the pickup truck of the skinheads that are harrassing Gary. Then you see the same plate on Steven Seagal's car as he drives away from saving Gary from the skinheads (incidentally, the front plate on his car is different than the back plate). The last time you see the same plate is on a Lexus driven by the guy in the all white suit who is going to buy the cocaine.
Revealing mistake: In the scene at the beginning of the film when the bus enters the village, you can see that the road signs are on the left side of the road (not facing the bus) and the continous line that separates the two ways is on the exit of the curve, not before the curve. This is because the action of the movie is set to happen in England but that scene was filmed in Romania, a country with right-hand traffic. (00:03:20)
Revealing mistake: During the bidding, the girls' pictures on the phone are obviously super imposed images and not really the picture phone screens.