Revealing mistake: Brayker shoots The Collector through the eye with an arrow just after he's collected the key from Roach. You can see the section of the arrow shaft that sticks out the back of The Collector's head bend as his head hits the floor after he falls over the upstairs railing and crashes through the coffee table.Phixius
Revealing mistake: The fight scene between Peter Kurten and Andy outside the gay bar is viewed from behind a metal gate. Peter smashes Andy's head into the gate twice. The bars of the metal gate bend towards the camera as if they are made of rubber.
Revealing mistake: After stealing the battery out of Durant's weapon near the end, as Westlake says "Batteries not included", you can see the actor's undamaged lips under the fake burn prosthetics on his face and mouth. (Look underneath the exposed teeth where his lips supposedly were burned off.).