It's amazing how many tough guys there are in the world who would fault Goetz for being in fear of his life in that situation.
The standard is, was he in fear of his life. In a given circumstance, that is going to be different for a 90lb., 75yr old woman vs. George Foreman.
Although it is illegal, I can't fault him for his trying a "coup 'de grace" on the one scumbag. If the roles were reversed, how much mercy would they have given him? IMO, when the shooting starts, all bets are off. Sort of like when Paul Newman wants to get the rules straight for the knife fight. "Rules? In a knife fight?" Gimme a break.