Don’t carry a gun unless you are absolutely prepared to use it. If you do draw down on someone, you had better have no doubts that you can pull the trigger. If you do pull the trigger, empty the gun. That’s what I was taught.
And then what do you do when the perp's accomplice pops up?
Empty guns are poor clubs.
No, shoot to stop the threat. This is key. As in “I was afraid for my life, and was shooting to stop the threat. That is all I will say until my lawyer is present.”
Note that stopping the threat may indeed require emptying the firearm from your perspective.