The fact that he didn't rage on you guys for him dying should have been enough of a sign of contrition, you making a comment simply rubbed salt in the wound.
I would have left for the same reason. This isn't overreacting, we just don't care about the group. My favorite LFD groups, are the ones that don't talk to each other. I don't even mind if you pull crap dps, just keep up, don't die to anything retarded and lets part company as quickly as possible.