When Norman and company are driving away from the zombies and cause Norman's father to crash, the police officer crashes into the Babcocks' car from the direction the van has just headed rather than where it has just come from.
When Norman and his classmates are rehearsing for the school play in the beginning of the movie, Norman is holding a script when he begins to read his part. However, after he is interrupted, he is no longer holding a script.
When Norman is hiding from his classmates in the bathroom stall, Alvin is in the stall next to him. While Mr. Prenderghast tells Norman what he needs to do to prevent the dead from rising, Alvin's feet can be seen in some shots, but not others even though he hasn't left the stall.
When Neil is watching his mother's aerobics DVD, it has white lines going across the screen as it is paused. VHS tapes did that but DVDs don't.
Mrs. Henscher witnesses the zombies entering the town hall through a side door, yet doesn't lead the angry mob in that way to get them.