Another master of theory. RG is full of BS.
I have never had a firearms instuctor, firarms competitor or firearms student tell me any different.
You shoot until the threat is over. Period.
Call any gunshop and they will tell you the exact same. Call any police officer or lawyer. They will tell you the same.
No one will tell you any different.
I forgot to mention.
When the police come for the report and to sweep up the mess, make sure you explain through your lawyer, you DID NOT SHOOT TO KILL.
You shot to stop the threat.