Ohio: Charter Member - COTH Hockey Clique & COTH Buffy Clique
I don't think there are any current rules written regarding air vests at all (thank gods). I do have a friend who fell and her air vest inflated and the way she described it, I'm not sure I'd be able to continue with it inflated. She said it hurt!
"Of course it's hard. It's supposed to be hard. It's the Hard that makes it great."
"Get up... Get out... Get Drunk. Repeat as needed." -- Spike
If it does inflate, it deflates pretty quickly. You'd have to have a pretty good "oops" to get it to inflate and still stay in the tack. The hybrid vest is all one piece so if you take it off you would be in violation of the vest rule. It would take some time to do that anyhow, with the pinney over top.
I don't know of any rules regarding the use of one while on course other than it must be worn over your required safety vest.
I can't speak for the Hit Air brand, but I know that in order for my vest to go off, its going to take A) quite ALOT of force (it takes a little more than 80 lbs of pressure for the lantern to detach) and B) I've got to be WAY and I mean WWAAYYY out of the tack for it to reach the end of its elastic.
In other words - for my vest to deploy I've done more than made a mistake at a fence by either getting too far up their neck or left behind a bit. I once came off course and went to get off with out unclipping my vest and I was on my tip toes but I was able to hug my horse and unclip with out it going off. Granted it was off my smaller resale project guy who is about 15.3 and not my prelim 17 hand guy, but you get the point.
Unless she had it done up too tight, I have not yet seen a vest go off when the rider actually stayed on the horse. And I can't picture mine vest going off with out me NEEDING it to go off.
I was concerned about just such a thing happening when I talked to the Point Two rep. She showed me how much it took for the vest to deploy, and I have never had the feeling since that I would have it 'accidentally' go off.
But like I said, I can't speak as to how your friend had theirs attached (maybe too tight?) or how much force it takes for the Hit Air, but I would not be worried in my hybrid.
I know there is alot of discuss back and forth on the whole air vest subject, but I like having an extra layer of safety there.