Right now you're espousing rampant paranoia. First you suggest that he would make up a story like this despite no precedent on his part at all. Then you say that the proof is that he didn't react violently to somebody spitting on him. Then you say that he's stupid for not doing that because the spitter might have been HIV-positive.
I live in a world where people are innocent until proven guilty, people are all generally trying to do the right thing, the average man on the street doesn't like physically hitting other people, and most people don't have deadly diseases, and that the ones that do don't spit.
I believe you are correct. I have no clue whether vaksel is American, but I do think Americans (I'm one) have absorbed--been fed?--a fair amount of hooey about HIV transmission and how to be "safe." Keep in mind, if you're old enough, AIDS was/is "that gay disease" and something quite a small number of injecting druggies were getting--as the "need" for a War on Drugs was building. I'm sorry to report, Americans are a fearful lot.
If you absolutely KNEW that someone had HIV and they spit (say) into your mouth, wouldn't you worry about it at least a little bit? Even though you know it's silly?
I think most humans are irrationally fearful about things like HIV.