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.