How else would I shoot? To maim? To injure? How can I tell if the threat is stopped? Shall I ask "Hey, have you had enough or are you still going to be a threat to me and my family?"
And as far as how to tell if a threat has ended, that’s not an easy thing to do and I can’t answer the question. But if you’re ever in a shooting, you may have to defend how you decided the threat was over, so it’s definitely something everyone should consider and seek training/education on. Thankfully, in Oklahoma the standard is primarily the reasonable belief of a threat, not whether there objectively was a threat (which is impossible to know in the moment, despite how easy it seems to armchair quarterbacks with the benefit of hindsight).