To all of you who are saying you wouldn't have shot because he was unarmed... how do you know he was unarmed? He could have had a knife tucked behind his shirt... and I know of plenty of guys who could kill you without a weapon. I'll be frank and say that if it was one of them and you'd messed with their wife you'd better gun them down if they were rushing you like that. If not it'd be you dead on the ground and him being arrested for murder - and he wouldn't need a weapon for that.
Totally depends on your state laws. I dont know about laws where you live or where this took place, but in NC you do NOT have the right to respond to a simple assault with deadly force. If you have the reasonable belief that the guy is going to kill you or do severe harm even though he's unarmed, or if you're covered by something like castle doctrine, things are different.