This movie is great, aside from the scene where the assault happens. Schizophrenics may get upset easily, but they are less violent than the normal populace. This portrayal points schizophrenics in a bad light, as if treating them like human beings is likely to lead to violence.
I'm not saying there are no violent schizophrenics, but they are so rare that to emphasize it so much here seems almost like the original author of this story was exaggerating Nathaniel's response out of fear or out of the fact that mentally ill people are possibly the last group of folks in the western world who don't get equal protection against slander, discrimination, or far worse. Note how they show almost no formative events leading to Nathaniel's condition. If they showed a broad pattern of abuse and/or trauma in his earlier life (which is absolutely the case with pretty much all paranoid schizophrenics and the abuse and trauma may seem small to the outsider but they were enough to shatter the schizophrenic's grasp of reality, so between genetic predisposition and traumatizing experiences in life, people generally aren't born with schizophreniform traits, at least not overt ones - it often takes triggers and usually some really rough experiences to bring out that kind of alienation and disassociation with reality).
If we treated schizophrenics like people instead of shunning and overmedicating them, we will almost certainly find that they are not so different from regular folks - they just see things differently, and some drug therapy combined with a good faith effort to find them fulfilling places in society would do far more than just labeling them and treating them like lesser people.