just as you draw your gun, leaving you an avenue of escape, many self defense laws are written such that you have to have tried to escape the threat before using deadly force.

And rightly so - while shooting someone just as you draw and just as they start to back away is one thing, but suppose he backs up and 3, 5 - 10 seconds expire before you shoot? 20? you have a couple verbal exchanges? You see him an hour later? What is the threshold that you weren't protecting yourself - you were judge and jury. Now the first and last example are pretty simple - but just where do you draw that line? That's one of the reasons many self defense laws require taking any possible escape route first.

As others have said IF you shoot, eliminate the threat and don't talk without a lawyer. Don't let the other story be "We were fighting and I backed off and then he came at me with a gun"