Other mistake: Mr. Gellar never ages. We see a flashback of him when he kills Sarah's Dad when Sarah was a little girl. When Sarah is a detective, he still looks the same.
Continuity mistake: After the doctor stitches and dresses his own eye, blood disappears, reappears and gets bigger and smaller through the dressing.
Visible crew/equipment: In many of the fight sequences, wires are visible on the actors when performing high jump kicks and/or acrobatics, for example, the first time the main character encounters zombies in hand to hand combat, a rope harness can be seen pulling the zombie back towards the tree.