No, I do not think it an act.
Helmuth has said so himself, citing the fact he was ultra competitive as a kid with family members and was a bad loser as a child. I think he is a bit on the spectrum, but not a ‘bad’ person.
There are a few areas he can’t seem to control himself – one is with bad beats and the other is his bragging (about money rich friends etc.). It used to drive me round the bend but I think its a sort of compulsive thing with him now, he just cant help himself at times.
However, outside of the poker table, no one has a bad word to say about him – he appears to be an affable sweet guy 90% of the time who is saddled with a couple of odd character traits.