I don't have Asperger's, so my opinion is meaningless in this regard, but I don't really understand how it could be that offensive. People with other conditions have it a lot worse; schizophrenics are often portrayed as violent psychotics and people with tourettes are consistently made out to be angry swearing lunatics. The "ass-burgers" joke doesn't even concern the condition or people with it, it just pokes fun at the word it's self.
That's why I don't see it as a big deal, they're making fun of the word, not the people with the condition.
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Un-ban Chever! Viva La Revolucion!