But (supposedly) he didn't know it was his son. And yeah, I would bring a gun to a knife fight. If I know there is a fight and there is for sure a knife, better believe I am not going to try and keep things even, I am trying to end things and I don't mean by killing.
The only questionable part would be if he shot without any warning or provocation. To me, that is the question. Yet they are saying the kid charged. His bad. All the way around. IMO.