Revealing mistake: When Andy was found dead from an overdose watch as the camera zooms out from him, he blinks. (00:34:10)
Continuity mistake: Toward the beginning when Philip Seymour Hoffman gets on the elevator with Lara Flynn Boyle, his tie is twisted all around but when he gets off, the tie has been fixed. He couldn't have fixed it because he was carrying two bags of groceries.
Visible crew/equipment: When the cops walk into the pedophile's living room, you can see a boom mic at the top of the screen.