Continuity mistake: In the scene where Jody is with her boyfriend on his bed, as he holds her neck the shot changes and he is holding her shoulder. This repeats a few times.
Revealing mistake: When Nick has swam back to his water scooter, he climbs up and drives away and the shark comes up behind him. But look carefully behind Nick as he is climbing. The nose of the shark is visible during the whole scene, right under the surface. This proves that the shark was a dummy, waiting to come up.
Continuity mistake: In the last scene to be filmed, with Orlock and Gretta, the candles on the dresser are alternately lit and then out, as Orlock's reflection is visible then not in the mirror.
Factual error: The actress Sasha Barrese is credited at the beginning of the movie as "Sasha Berrese".
Revealing mistake: In the end, when Paula kills Hein, you can see in close-ups that the scars on his face are on tape and not on his skin.
Continuity mistake: When Marci escapes from the web in the elevator shaft, she closes the door on the spider chasing her. In that sequence, the door closes automatically; in other scenes, the door opens and closes manually.
Continuity mistake: In one scene we see a police officer investigating his colleague's disappearance. In the long shot we see him walking towards the other police car and it can be seen that the number plate is a fake. A fake paper number plate has been placed over the original number plate. When the wind blows you can see the side of the paper blowing in the wind. (01:16:05)
Revealing mistake: When Tomie's head is cut off and her body falls into the wheelchair, look closely - it's clear her body is just a painted mannequin. The skin has a plastic-y sheen to it, and the body itself is entirely too stiff and rigid.