Continuity: When Bill and Kylie flee her house and get into the police car, a zombie vomits acid on Bill's driver side window. In subsequent shots the window is clean.
Errors made by characters (possibly deliberate errors by the filmmakers): Several of the characters slip in and out of their accents in the second half of the movie.
Factual errors: After Grant comes home with the truckload of meat, Elizabeth notices the lock on the cellar door. The lock plate is not secured to the door frame, so the padlock is useless.