Found a link to this news site http://www.npr.org/templates/story/story.php?storyId=9496562 at this post where there was another bike/cyclist conflict. I think I’ve seen examples of both cases of where the driver was at fault and the cyclists was at fault and also where both where at fault in an accident.
I would say that we should defend ourselves, and not instigating fights, if someone just about ran you over, then call the police, get their license plate report them, DO NOT try to act as judge jury and executioner out there on the road, no matter how mad or right you are, or you could find yourself dead or in jail. But if a crazy driver jumps out of his car and tries to take you out with a tire iron, then by all means take him out first to defend yourself.
There’s a very fine line between defending yourself and starting a fighting and calming a situation down.