Thank goodness the homeowner will live.
Cop: “Drop your weapon!! Drop your weapon!!”
How hard is that?
But I still can’t say that up until the point of abuse of the victim and the beginnings of a cover-up it’s anything but a tragic mistake in a highly tense and chaotic situation.
This exact situation is covered in some detail in Massad Ayoob’s “Judicious Use of Deadly Force” class, about ways to help insure that first-responders don’t mistake you for the bad guy.