So many different "what-ifs" here. Each situations is different, as the second poster alluded to. Each case will be completely different. Some things to consider though.
1. Check your state laws. This is number one on the list for a reason. Each state is different (some allow lethal force to prevent a felony, others require you to be in fear for your life. Some require you to fear for your life in order to use ANY force.).
2. Sometimes any force can be illegal and the only difference will be what you're charged with. But remember, assault with a deadly weapon includes weapons from handguns to frying pans.
3. Sometimes non-lethal force is more likely to get you into trouble than lethal force. This boggles some people, but look at the classic example of "shoot the criminal in the leg" in an effort to use non-lethal force. So you shoot a BG in the leg to incapacitate him. What if you had missed? What if you hit his femoral artery that runs down his leg? What if the bullet had ricocheted off his femur and up into his thoracic cavity? Also, you just shot the guy in the leg? How fearful of this person were you? You obviously didn't fear for your life, he obviously wasn't THAT much of a threat to you, but you chose to shoot him and risk killing him anyways? And I think you see where the prosecutor would go with this one as well as where you would go: jail.
4. And here is the bottom line for a lot of people: Are you, in most cases, better off legally using non-lethal force? Sure. Are you, in most cases, better off
health-wise using non-lethal force? Well that depends
5. Check your state laws. This is number five on the list for a reason. Each state is different (some allow lethal force to prevent a felony, others require you to be in fear for your life. Some require you to fear for your life in order to use ANY force.).