Due to the length of shooting, the actor's hair length and beards noticeably change.
The Assistant Director's watch changes from wrist to wrist.
After the Guy Who Dies First on Zombie 87 hug outside the warehouse, the Guy Who Dies First has a considerable amount of blood on his shirt. In the next scene, it's gone.
When examining the Director's dead body, the Producer jumps from the foreground to background between shots.
The hammer that the Assistant Director grabs from the van is not the same hammer he brings into the club.
In their first appearances, both the Gaffer and the Guy Who Dies First looks directly into the camera.
When the Mormon Zombie is hit with the bat after biting the Director, there is no blood splatter or even sound of contact.
Some of the lines outside of the warehouse as well as some on the roof are out of sync.
Just before the end of Act I, one of the camera operators is very clearly visible at the bottom of the screen.