I have to agree with Roberta (Whom I didn't get the chance to meet) and Uncle on the rule 3 violations. The folks who put out the display guns are humans after all, so although highly unlikely, it's not impossible for a round to find its way into one of the thousands of guns on the floor. Just because it's on the display floor doesn't mean you shouldn't verify that it's unloaded before dry firing, the same as you would with your personal weapon. Who knows, maybe I'm wrong since this was my 1st time at one of these.
And honestly, the Para rep freaked me out when he was showing off their new piston AR's. He picked it up and pointed it directly at my chest. Rule 2 damnit! (yes, I know it's virtually impossible to handle a gun and not violate said rule at the convention, but I still don't like staring down the muzzle end of a rifle from a foot away)