Audio problem: When Patrick Bateman is exercising and watching The Texas Chainsaw Massacre, the audio does not match up with the actual film. (00:37:05)
Visible crew/equipment: When Patrick Bateman is showing Detective Kimball out of his office, the boom microphone can be seen poking into the shot on the other side of Bateman's interior office window. (00:36:46)
Continuity mistake: When Patrick Bateman murders Paul Allen, the collar on his raincoat is either up or down, depending on the shot. (00:27:49)
Revealing mistake: When Patrick opens his fridge to offer Jean some sorbet, you can see the decapitated head of a woman in the fridge. If you pay close attention, you can see the head is moving a little. (00:59:36)
Suggested correction: It's a prop head resting on a freezer shelf. It could simply be that opening the freezer door causes the head to sway a little, similar to if you had an egg, lemon, or something else that didn't have a flat bottom resting on a shelf inside a fridge.
No, the way it was filmed was with the actual actress putting her head up through a hole in shelf. It's her head moving.