I have a hard time following this logic..Although I see where you are coming from, you are either justified in using lethal force, or you are not. If the ammo is "specially loaded killer ammo" or any other ammo that is legal to own, the topic is irrelevant. A private citizen has no standards of escalation of force. If the ammo happens to be more deadly, then it just means the individual made a better choice in ammo.
Under that logic why would we not all use fmj ammo instead of hollowpoints for self defense? Or shoot someone in the knee rather than center of mass to stop a threat? Perhaps I am mistaken, but those are my thoughts.
I asked Massad Ayoob in a pm on another forum about this. He cited several cases with over zealous DA's.
His argument was convincing enough that I only carry factory ammo.