Revealing mistake: There is an obvious shot splice of the elevator reaching the floor with Jack on it and one without him. The position of the elevator changes ever so slightly and you can tell the difference in the light coming from the elevator. (01:12:30)
Revealing mistake: When the chopper is about to shoot out the elevator, on the right is a pair of guns and on the left a gatling gun. At the end of the scene the guns have switched places, with the pair being on the left and the gatling gun on the right. Flipped shot. (01:16:10)
Revealing mistake: After Slater jumps out of the house and it explodes, when the cop car flips over, the air ram used to flip it over is visible.