Poor treatment of psychosis.
I really like this movie, but one part bugs me...if Warwick is truly schizophrenic, and takes meds, ostensibly so that the voices and hallucinations disappear and he can function at work, then wouldn't he NOT have perfect recall of everything that happened? Would he really be able to act perfectly normal in front of colleagues, but then "switch on" the psychosis again at home?
Mental illness isn't something you can turn on and off like that.
Or...is it possible he KNOWS that the party guests aren't really there? For example, whey does he go from plate to plate, eating up their portions if he thinks they are REALLY sitting there having dinner with him?