[KLRANGL]

I see a lot of the what ifs of the "execution-no-shoot" are related to where the BG's gun was while trying to stand back up again.
Take this fictional scenario: Unarmed BG, who is 16 but looks like a linebacker (as some do) walks towards a crippled man yelling "im going to kill you!" It is my understanding that, if the physically disabled man shoots, it would be a good shot. Much like a women shooting an unarmed but overpowering attacker.
If this is indeed the case, the location of the sidearm becomes irrelevant. (Note my assumption of the 16 year old being physically dominant)

What does become relevant was the state of the BG and if he indeed posed a threat. Im inclined to think that a guy who would walk into a store, yell "you're dead!" and start shooting without provocation should be considered extremely dangerous, and would almost be justification enough to "empty the magazine" when he's trying to get back up.

I remember a while back seeing a security video on here where a security guard at a gas station or some such engaged two BGs who came in guns blazing (it was somewhere in Asia I beleive). He shot one BG, and ran after the second, but after running past the one downed BG, he was shot and killed. The assumption was the downed BG was no longer a threat, and it killed him.
Not sure if that's totally relevant, but you can see the parallel to this case.