Factual error: Unless Marion has a ridiculously large front room, the guns should have come down as he was blasting the zombie with the shotgun.
Factual error: In the convenience store scene, "Chip" Chipperson walks in and cops a shovel in the top of the head. Then he starts walking forward and a sign stops him, and the shovel pulls out, tearing off his face. Shouldn't have it torn off the front of his head?