The technicality of the self-defense claim is noted.

The robber had run from an armed clerk, and was chased outside the store. While being shot at by the clerk, the robber returned fire and the clerk died.

…when the guy ran away, the concept of the clerk being reasonably afraid, that changed considerably. Now you have a serious felony, what the robber did, but you don’t get to execute the guy under those circumstances. So the robber then obtained the right to self-defense.

I wrote and gave talks about this scenario back in 2012, when working on active defence. We referred to it as knowing when defensive acts being indefensible, using a case known as “the fourth bullet”.