Hallo TailGator -
"Kiss the pavement," you're right, a touch colorful.
Stop and drop --- for the perp threatening armed robbery --- Suffice it to say I would make it abundantly clear that I wanted them on the ground, facedown, arms and legs spread. Whether they comply is up to them. If the BG withdraws, thats fine, I am in no danger and my gun is still concealed. If he attacks, I defend myself, meaning I draw and shoot.
Stop and back-off (withdraw) --- Is for when I am 100% sure the person moving towards me is dangerous but has not verbally threatened me or shown a weapon. If he continues moving towards me I would try to withdraw and put distance between us. If he attacks, I defend myself.
(Example --- My wife was once pushing the baby stroller late at night. She heard a quick succession of footfalls behind her, she wheeled and in a firm clear voice shouted -- "STOP, BACK OFF." It worked.)
"You yourself indicated that when an assailant sees you are armed he might surrender or flee (if you can forgive the paraphrase)." [TailGator] Did not say that, hope I did not imply that.
The only time the assailant will see my gun is when it is drawn...if he sees it at all...and I don't draw unless I am under deadly attack...point being the bad guy will be attacking me, likely 3-8 feet from me...the perp has been warned, all I can do now is draw and fire.
I would never shoot someone who is withdrawing, fleeing, or otherwise surrendering. But understand, any talking I do, my gun is concealed. It only comes out when I have to use it.
When the gun comes out, it goes boom, because if it doesn't go boom, I get cut, or shot, or battered, etc.
Hope this clarifies things, thanks for your comments.