I hope that I am never in this situation, but if it was me, I would of drawn down on the guy. (keep in mind I only go in stores that allow me to carry!)
Really?
Seems a bit extreme to me.
I would probably have said "hey do you mind not pointing that thing at people, it makes me uncomfortable" and then see where it goes from there. I'm pretty sure the clerk PROBABLY cleared the gun before handing it to anyone. So while it's still REALLY stupid the way the guy acted, I don't think I'd "draw down" on him.