Corrected entry: The construction workers have run out of nails for the nail machine. But when the actors come, the machine is full of nails again.
Corrected entry: In the scene at the custom car shop, Lori hits a lever that causes the black van to drop down on the car lift. Those lifts have special devices within the lift rails that prevent that kind of situation from happening. When she hit the lever, the car may have dropped a couple or a few inches but not drop almost all the way back. The safety mechanisms would have engaged instantly.fiveonfridays
Corrected entry: In the scene with the escalator, the shots showing its inner workings near the bottom depict many chains and a couple of rollers sitting out wily nilly. Real escalators only have a simple return wheel (or gears on the sides) and a bunch of empty space at the bottom. (01:08:15)
Corrected entry: In the mall scene where Nick's trying to keep Lori from going into the mechanism of the escalator, her legs are being shredded (crushed) in the machine and blood is coming out of her mouth. Medically speaking that can happen if there is internal bleeding, or a wound relatively close to the head, but this would not happen with a broken leg.