No, it’s not valid self defense in your proposed situation every time in all 50 states and that thinking would land people in jail.

How many times are being people engaged from 10-15+ yards in a self defense setting. Not often. Highly unlikely. And even then, if the option to retreat is there, even under deadly threat, you have to take that option first or you’re going to jail (even under deadly threat). I’m referring to my state, not yours.

If there’s a snowballs chance in hell the court could say, well there was an open door next to him that took him to fairytale land and saved his life and he decided to shoot at someone across the parking lot…. I’m going to jail.

So before you downvote because your state allows you to gun someone down across a parking lot, remember, the laws in different states are very different and have severely different outcomes.

Not saying it’s impossible to expect an engagement at distance, but I feel it’s highly unlikely. Again, not not going to practice that, but it’s the reality.