I have been in a threat situation, and it ain't pretty. What with the huge jolt of adrenaline that hits your system, and the sheer fear engendered by a large stranger coming at you yelling threats, your brain more or less goes on autopilot. If you've been well trained, you'll function fairly well, but there is no logical thought going on. There's no time.
Most people just keep pulling the trigger until it doesn't go "bang" any more. And it looks like the judge realizes the truth of this.
The only reason my assailant didn't get filled full of lead is that he ran as soon as he saw the muzzle of the .45 trained on him. (Guess he wasn't hopped up on morphine.)