"Could have" doesn't cut it. No reporting I've seen says anything about the victim being punched more than once. And regardless, the victim was not even in the area when the shots, including the initial warning shot, was fired. Deadly force to stop the theft of a car is NOT justified, no matter what kind of spin you want to put on it. Since the victim was not in the area, not being assaulted anymore, take him out of the equation. The shooter was no longer intervening to protect his life, he was no longer in danger. Sure, if he was still getting beaten by the suspect, then an intervention would be appropriate, but HE WASN'T EVEN IN THE AREA. That is exactly the same as me coming to your house saying the guy in the front yard just punched me and you going outside and shooting him. Not justified in that scenario, right?