I'm familiar with the term. It's my understanding that face-to-face communications are the most impacted areas of human interaction for folks with this condition, and that online communications are easier for them, because they're on mostly equal footing with the folks they're talking to (no one can see anybodies facial expressions on the net, and so only the words themselves matter). It's one of the reasons so many of them find their way into computing and other fields that don't require direct human interaction. With Bram's intelligence, I'm certain he would be capable of effectively simulating normal human interactions online (and I've spoken to him online and he seemed perfectly normal, though he probably wasn't in a frustrated mental state at the time). He could have chosen to approach things with more civility, regardless of whether he has Asperger's or some other condition that makes human interaction in the real world difficult. The loosely realtime nature of IRC allows time for thinking over what you're saying, considering the implications, and thinking through how it will appear to others.
In short, I'm saying that I don't think Bram should get (or would be right to expect) a pass for being an asshole to a volunteer on FreeNode, regardless of whether he has Asperger's or not. Being an asshole isn't OK, even if you have a condition that makes it easier to be one without noticing. It just means you need to be more mindful of your behavior, since it's no one else's job to do it for you.