I got in a street fight once when a guy with horrible road rage was CONVINCED that I cut him off. The guy came running up to my window, tried opening my door and everything. I got out and the guy instantly gets in my face, yelling at me and then starts pushing me. I can take pushing and told the guy he needs to back the fuck off and leave because I did not cut him off. The guy then grabbed my neck and tried choking me, that's when I hit him and pushed him off me. Once I hit him then the guy tries getting me into a head lock and telling me that he is going to kill me. I got away from his "head lock" and while he was still down on the ground I kicked him in his nuts, in his ribs and made sure he wasn't going to get back up.
Around here, if I remember right, when kicking someone you could be charged with using a deadly weapon, but I felt completely justified since this guy not only threatened my life but in turn threatened my old lady's life who was with me, who knows what he would have done to her if i got knocked out or something. I got out of there before the cops could show up or be called, 'twas a busy street that this took place on in broad daylight.
Bottom line is if someone threatens your life, whether they mean to be intimidating or actually mean it, you should be able to do whatever the fuck it takes to survive. Survival of the fittest doesn't go for just animals. You never know what someone else is thinking and if they feel strong enough to tell someone they will take their life then they deserve every bit of ass kicking they get.