Continuity mistake: When Bateman goes crazy and flees into his office, his hair is very messed up. However just after he sings and goes to his office, it is quite obvious his hair has been redone and gelled again.
Visible crew/equipment: In the scene where Patrick Bateman is walking the streets, just before that encounter with the lady who is waiting for the red light to change, you can see the camera crew reflected on the store windows.
Continuity mistake: In the scene where Patrick is in his office working on a crossword puzzle before talking to Jean, he is writing with his right hand. When the shot changes to the reflection of Patrick's glasses, the reflection shown is as if he is using his left hand. The reflection isn't a mirror image as it should be.
Character mistake: Patrick, being the music buff that he is, mistakenly claims that Huey Lewis' Fore! came out in 1987, when it was actually released in 1986.
Chosen answer: He tortures them. You can see them bleeding as they leave. Christy also says she had to have surgery afterwards.
LorgSkyegon