Patzer

Angus kills Barbara by slicing her chest vertically to remove her heart. When she rises as a zombie, she has head wounds and a horizontal stomach slash, but nothing on her chest.

Roddy Piper's t-shirt changes color many times through the movie.

Sarah is supposedly on the bus sitting a few rows behind Shane Douglas. However, a few shots earlier, nobody is sitting anywhere in the entire back half of the bus.

Roddy Piper locks the Rodman zombie in the freezer. In the next scene, where a woman in a wheelchair is used as a battering ram, the Rodman zombie is among the group of zombies.