Ape Agitator posted:

I don't know. Have you been to Vietnam?


Bateman is completly psychotic and has essentially been living out most of the movie as pure fantasy. As the film progresses, he goes further off the rails running through hallways with a chainsaw and having ATMs request kittens. By the end it kind of comes crashing down as his phone call to the lawyer provides independent corroboration that he hasn't killed Paul Allen after all.

There is a case to be made that some of his actions are real but you really can never know. Realistically, since Paul Allen is the trigger, it's likely he's just a whackjob that beats up prostitutes and dreams of killing his peers.