Droptine,
Now that I see the rest of the story, I think you did exactly the right thing. I'm like you in that I feel free to offer my opinion, but don't seek confrontation. If someone confronts me, I'll generally try to defuse the situation. But if someone's determined to take it to the physical level, I don't want togive them the satisfaction of having someone back down to their bullying. I'm not that big (5'9, 185 lbs), and most people would peg me at closer to 160 lbs (what can I say? I'm dense, as anyone who knows me will attest) but I can sure as he!! fight. Getting an a$$whooping from someone they thought was an easy target may make them think about picking a fight next time.
Sounds to me like you told him something he knew deep down and it hurt. Good for you! Maybe he'll think about it before he shoots next time.