Revealing mistake: As Drew Barrymore is running from the killer outside he stabs her. If you look closely it is very easy to tell it is a rubber knife, because you see it bend off of her. (00:10:20)
Revealing mistake: When the huge alien ship settles over the White House there is an exterior wideshot of the grounds. At the bottom of this shot it's funny how there are many tourists - adults and children, just milling around in front of the gate and across the street with a van driving along between the two sides, and not one has any sort of reaction to the alien ship. This real shot of the White House (some shots had smaller-scale models) had the CG ship edited in during post production. (Visible on fullscreen DVD.)
Revealing mistake: While driving the red truck through the rolling house, Dorothy is mounted on the back of the truck. There are some very sensitive and fragile instruments located on the top sides of Dorothy that stick up above the cab of the truck. These would certainly have been torn off while crashing through the walls of the house, turning Dorothy into a useless pile of junk.
Revealing mistake: When George Clooney is talking to Juliette Lewis towards the end of the film, it is painfully obvious that his tattoo has been smudged. (01:40:35)
Revealing mistake: From the front view of Karen's gun, you can see empty chambers.
Revealing mistake: When Mason is having his hair cut, after finishing up, he is talking to Womack and turns his back on him. If you look at the back of Mason's neck, it is clear that he's not just been freshly shorn; there are whorls of hair just above his collar. (Either that, or the barber was terrible at his job).
Revealing mistake: When Tisean has just died and Stoney is getting out the car, Tisean is still breathing.
Revealing mistake: After the Martian who is dressed up as a women spits a finger in the fish tank a bit of the Martian's mask near its mouth is torn away. As she chews the nitrogen gum the human lips move but her real teeth don't. (01:04:20)
Revealing mistake: When Arnie jumps from the plane, notice the stunt double. He weighs about half of what Arnie would, and has no muscles. (00:55:10)
Revealing mistake: Hamlet is killed and in the next scene is being carried with his arms stiff to his sides. The men carrying him go over a bump, jolting Hamlet, and he blinks.
Revealing mistake: At the end of the film Vanessa gets crazy because Bob kills her grandma, and she starts beating him up in the caravan, hitting him and throwing various stuff at him. Throughout the scene, Reese Witherspoon's' stunt double is really obvious. Her hair looks completely different!!!
Revealing mistake: After Lucy discovers Mrs. Bradley in her bed, as she fights off and runs from Patricia, it is obvious that she wears knee pads for these shots.
Revealing mistake: When Liam Neeson is on the boat on his return from England there is a shot of the water and part of the boat where you can see a modern CCTV camera on the side of one of the masts - rather advanced for the time the film was set. (01:21:20)
Revealing mistake: When the Oceanic 747 attempts to make its first landing, you can tell that the 'hole' on the side of the aircraft is simply painted on.
Revealing mistake: Painfully obvious bluescreen/CGI effect when Snake makes the motorcycle jump into the back of the pickup truck in Cuervo's motorcade. (00:32:45 - 01:08:20)
Revealing mistake: When the guy that was shot in the chopper is falling, you can see the protective, yet flaming mask on his face.
Revealing mistake: Towards the end of the film when Gary Sinese shoots the guys in the white van, when he shoots the bald guy, as he falls out the door you can see the squib vest protrude from under his shirt.
Revealing mistake: When the second helicopter is blown up you can see it is the same helicopter that was blown up the first time. The writing on the helicopter is reversed compared to the first helicopter. (00:21:10)
Revealing mistake: When the car at the end flips over, you can see a circular object underneath the vehicle, about the size of a tyre (very obvious in slow motion). This is the device that "lifts" the vehicle for it to flip on one side, timed with the appropriate explosion.
Revealing mistake: In the deflector dish scene when Worf chops the Borg's arm off with his mek'leth, the blade obviously doesn't even touch the Borg. (01:09:45)
Suggested correction: Not all barbers do neck hairs. The barber probably didn't want agitate anyone by taking too long.
lionhead