Visible crew/equipment: In the scene after Patrick Bateman's second encounter with the detective in his office, we see Bateman having sex at Courtney's apartment. After he rolls off her, Bateman approaches the large, stand-up mirror in the bedroom. In the upper right hand corner of the mirror, a boom microphone can clearly be seen moving around to pick up Christian Bale's lines. The next time we get the same long shot, the microphone is gone. (00:52:45)
Other mistake: Several close-ups of the business cards of Patrick Bateman and his associates reveal a misspelling of the word "Acquisitions" (the "c" is missing - not a small error, given that this is the name of their department). (00:18:35)
Suggested correction: The business cards seen in that scene are supposed to be bad. An expert on business cards once reviewed the scene for a YouTube video and pointed out many aesthetic flaws in them, including this one. The subtle joke is that Patrick and his friends are all pretentious and deluded, thinking they're masters of style while they can't even spell words right. This is more explicit in the book, where paying close attention to the clothing Bateman describes, people's outfits make no sense.
Continuity mistake: When Bateman goes to Paul's apartment to pack up his stuff to "send him to London" after killing him, as he is packing the bathroom light is off and then about 2 seconds later the light has come on by itself with him nowhere near the room. (00:30:50)
Continuity mistake: When the detective is in Patrick's office questioning him about Paul Allen's disappearance, there is a bottle and a glass on the table. A glass ashtray appears by the bottle and the glass then disappears between shots. (00:34:20 - 00:35:30)
Continuity mistake: When Bryce pulls out Paul Allen's card to show it to Patrick, he holds it in different ways between shots. (00:19:44)
Visible crew/equipment: When Patrick brings Sabrina into his apartment for a threesome with Christie, he says to her "Not quite blonde, are you?" and you can see the shadow of the boom microphone fall across the wall. (00:40:19)
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)
