And not to defend uncontrolled rage (oxymoron), but usually rage isn't rational and we do stupid stuff, sometimes inexcusable stuff. We've all lost it at one time or another, and regretted the things we've said. But this doesn't mean that the things we've said were necessarily representing who we are, just the things we wanted to use to hurt people. Yeah, it's all gray, but what isn't.
Interestingly, I just saw a program on Tourette's syndrome, and there was a sufferer that could not control his use of profanity and racially derogatory remarks. He had been working at a hospital for like twenty years and his coworkers all knew he was a good person. But as his condition worsened and the profanities and racist remarks increased, it became difficult for these same coworkers to see past his condition. They still knew deep down that he didn't mean the things he said, but the words hurt too much to ignore. Just an interesting situation with a slight tangential association to the thread.
Yeah, MR lost it and shouldn't have said what he did, but for me, I will let MR's response speak for who he really is.