Continuity mistake: When Lionel's mum gets bitten at the zoo, the colour of her sleeve material changes from black/dark blue to light blue. (00:17:45)
Continuity mistake: The zombie baby keeps changing size throughout the movie.
Continuity mistake: Despite being absolutely drenched with blood during the zombie massacre, Lionel's sweater and pants are completely dry in all the following scenes. His pants are amazingly clean, too. (01:25:45 - 01:32:00)
Continuity mistake: Just after the Kung-Fu Priest scene, and Lionel is feeding the zombies tranquilized porridge, Nurse McTevish swallows some and it pours out of her throat. After Lionel has put it into the nurses throat, the porridge has disappeared.
Continuity mistake: When Paquita is trying to get Rita back on her feet, and the top of that zombie's head slides toward them, Paquita kicks it. It flips onto its side, but the next shot has it sliding right way up again. (01:25:25)
Continuity mistake: In one scene Lionel is cleaning bloody footprints off the floor. Then Paquita comes round, and Vera eats her dog. Then Vera attacks Lionel, and they roll down the stairs. As they roll down the stairs you can see the footprints are now different from before. (00:28:10 - 00:29:45)
Continuity mistake: During the scene in which Lionel is in the basement attempting to sedate the nurse and his mother, he is startled by a falling crockery. After the rat runs past him, the nurse attacks him. He stabs her in the nose with the syringe, however, the following shots show the syringe is embedded in her eye.
Continuity mistake: When the top of the zombie's head slides toward Rita, the floor around it is clean. As soon as the shot changes, there's blood all around it, and then it changes again, when Paquita kicks it. (01:25:20)