Il Ling New and I were taking a couples defense class at Gunsite, called Team Tactics For Two. In a force-on-force segment we were told to leave our house and walk to our vehicle, which was parked some 20 yards away. As we got about half way to the truck, a "bad guy" came from around the side of the building, on my side, and I engaged him. Il Ling was soon occupied with a second "bad guy" coming from her direction. Shortly, it became apparent they were both armed and we took care of business.
Walking away from that training segment, I was pretty proud of the way we had handled the situation. Proud, that is, until Range Master Charley McNeel came up and asked a simple question. "When you first saw the bad guy, before any guns were drawn, why didn't you just go back into the house? Wouldn't that have been your most defendable position?"
I looked at Charlie and said, "Oh," in the most intelligent fashion I could muster.
And he was exactly right, from inside the house we could have found good cover and had plenty of time to call 911. Besides, if it had actually been our house, we would have known the layout much better than the criminals and we would have immediately armed ourselves with shotguns. Just about all of the advantage would have been ours.
Here is another scenario to consider. You are at home, at night, and decide to go out into the carport and get something out of your car. As you step outside, you are immediately aware of someone standing in the darkness just at the edge of the carport. You put your hand on your defensive handgun and order him to identify himself. Nothing. You tell him to let you see his hands. Nothing. You tell him to go away. Still, nothing.
If you advance and engage (it is, after all, your house), you may end up shooting an unarmed individual. He might be just a drunk. He might be a person who is disoriented for some reason. He could end up being any number of things that don't require shooting.
The smart move is to just quickly go back inside, lock the door and call the cops. If he comes after you and tries to break in, the scenario is altered and you may actually have grounds for firing. But, at least now you have real reason to believe that your life is in danger.
The same can be said for coming out of a restaurant or movie theater and encountering some street punks who are obviously up to no good. Your first move should be to attempt go back inside, call the police and let them handle it. Standing up and doing the John Wayne bit when it is not necessary is not smart.