Armor value on a spit?
I've seen their wings come off out-of-hand more often than I see them get damaged from ordinance. In fact, I get more kills on them that way than I do from shooting them (Insert comment about my gunnery here ____________)
It must be related to the amount of players in the arena. When it's very busy I (usually) see more buggy events.
I have, however, noticed what you mentioned about tracked GV's.
I don't know too much about the mechanics of damage modeling (except damage that I receive, of which I know a lot about. I know there is plenty of it, usually)