Our hero drew and the bad guy stopped, arms out to his side, and asked "What're you gonna do? Shoot me?" He must've twitched the wrong way, because the good guy promptly did.
It was at that point that things went pear-shaped with the arrival of the Good Samaritan bystander who immediately started Samaritan-ing the wrong dude: "Hey, man! You just shot this guy!" Good Guy tries to explain what happened, while not letting Samaritan get too close. Samaritan interprets Good Guy's refusal to let him get close as being a sketchy guilty dude trying to get away.
Good Samaritan decides he's going to play hero and detain Good Guy for the cops. A tussle for the gun erupts, likely because of Good Guy's understandable reluctance to shoot Good Samaritan, and so Good Samaritan ends up stabbed fuckity-eleven times in the retention fight for the gun. It was ugly.
