Second, if a vendor gets on your case about touching before asking permission just simply move on. There will surely be another vendor down the line, with the same gun, that will be more friendly to the customer. The "ask before you touch" rule is simply another tactic a bunch of these vendors use to make themselves feel important.
I can tell that you've never been a dealer at the shows. When I first started selling at the shows, I hated the "don't touch my stuff" attitude that the dealers had too. So I had a total hands on, play with anything you want policy. I changed that REALLY FAST!
There's a reason the dealers don't want people handling their stuff and it has nothing to do with control. It has to do with the fact that while most people are decent and have some common sense, a LOT of them don't. They tear stuff up, take it apart, break it, rip packaging apart, scramble stuff so that you lose sales because others can't find it, etc.
I learned my lesson the hard way and ended up being one of the "don't touch my stuff" dealers that I used to dislike. Because I understood why they did it.
A little understanding goes a long way in this world. And rarely are things the way they seem on the surface.
A couple years back we had an incident where a dealer was selling some rare, collectible revolvers. They had never been turned, which of course adds to the value. A customer came along and cocked and dry fired them before the dealer noticed. This dropped their value quite a bit. The customer said "I didn't know" and walked off. The dealer took a big loss over it. I've had them open the daylight filter on night vision scopes and point them at the lights and turn them on. I end up having to replace an expensive tube because the customer "didn't know". Yet if I have no batteries in them, they don't sell. How is that fair to the dealer?