Could you be more specific about which details give you this impression, and what you mean by it? I haven't interacted with Gelman personally, but having read both the NYT article and his response to it (as well as reading his blog and regularly his papers occasionally) I see him as someone who cares about "the truth" more than social niceties, but not as someone who gets any joy out of causing harm to others (which would be my definition of a "huge asshole").