Don't minimize it. Using "autist" as a derogatory term was simply outside the realm of basic civility. While this doesn't excuse threats of bodily harm, it was the first punch, as it were. The mods have spoken. Chill, move on.
Although to be honest, A-words in general do seem to be a trigger for Easterhay. I recall he also threw a complete wobbly when I used the word "astute" to compliment his son once. True story.