Revealing mistake: The guy who takes the trash out of the club and bumps into Michael Myers, gets his head stamped on and squished, later appears in the film as the person introducing the Halloween party.
Revealing mistake: Just after the Buick spins around to knock the trailer loose, we see the Buick speeding away backwards alongside the truck. If you look carefully you can see the REAR tires are steering, not the fronts. This car was modified with the body mounted backwards on the chassis because the transmission only has one reverse gear, so to get the speed and handling needed, the car had to be going 'forward' with a 'backward' body. (00:05:30)
Revealing mistake: When the soldier is tempering, you can see sparks fly before the hammer hits the metal.
Revealing mistake: In the scenes where Sam 1 and Sam 2 are in touch, the double is completely wrong. Wrong hair, wrong profile and wrong hind end.
Revealing mistake: When both Lisbeth and Mikael open their Apple Mac computers and use them, the little apples on the outside should light up, but they don't - neither computer does; they're switched off or not powered up - Mikael even goes to the trouble of connecting his to a power cord.
Revealing mistake: When they drive out of Vegas, headed for Witch Mountain, there is a shot that appears to be made with a camera on a mobile cherry picker. The camera sweeps across the road and up high, watching as the vehicle passes under the camera. As it passes the camera, you can see a trail of dust that was kicked up by the cherry picker. It crosses the road and is still floating in the air from a recent crossing.
Revealing mistake: Nick's reflection is seen in the shiny ceiling, but the guns floating above him have none, revealing this to be a CG effect. (00:54:50)
Revealing mistake: In the evil woman's dramatic scene after she kills the children, her knife flops around like it is made of rubber, but sounds solid when she throws it in the sink. (01:22:35)
Revealing mistake: After the 4 have been tied up and babyface has killed their captors, he grabs Alexa by the neck. There is a shot of him from behind and you can see the make up covering the back of his head/neck coming up above his collar.
Revealing mistake: When Steven Seagal makes his triumphant entrance in the credits, his sword misses the first zombie he supposedly hacks (right after "Written by"), by a mile. (00:03:20)
Revealing mistake: The movie shows in Matrix-esque slo-mo the double baton swing Goku dodges, from Fuller and his goon. They are nowhere near hitting each other, and yet, this missed baseball-bat swing causes them to KO each other in close-up. (00:16:55)
Revealing mistake: When Needy uses her key to unlock the door, you can see the door is already open. (00:58:07)
Revealing mistake: When Julie is trapped in the bathroom with the "ghost girl" she is saved when some other girls come in and switch on the lights. However, if you watch the girl who flicks the light switches you can see the switches are already in the "on" position (pointed upwards) and she simply mimes flicking them up. (00:26:47)
Revealing mistake: While breaking into the vault Gabe and Ripley use two ratchets to pull the large block that they cut out of the wall. The block moves as they pull the ratchet arm back. The block however moves only at the end of the pull for the second pull which makes no sense. This was an obvious timing error from whatever was really doing the pulling. The ratchet itself would've only pulled the block an inch at best. Additionally, when the block is almost out it shifts unnaturally showing that it was not made out of concrete. (00:56:45)