I think we can and should be a little more careful about words. Not that "Asperger's scale" is any sort of insult, but we are given a LOT of text for why Henry acts the way he does, emotionally. He's someone who arrived in New York with his wife and children in 1981. So when he came out and meets Walter, the AIDS epidemic is already taking up their entire world. The fact that Walter cares for so many of their dying friends seems to exacerbate the fear and terror that Henry feels about intimacy.