This is why we need replays.
Assuming, for the sake of argument, that stats/connectivity issues are ironed out: if I'm playing a Pantheon game and somebody does this to me, I will likely lose. (Assuming that the exploiter has worked out a method of reducing his/her risk while performing the exploit, and can therefore maximize its effectiveness.) I don't have a lot of other options:
* I can vote to concede. Probably what's going to happen, in any case; this just means I lose faster.
* I can leave the game, but now I have a ragequit on my record and the exploiter still gets a win.
* I can't kickvote the player; they're not on my team, and I don't think GPG should implement a "kick members of the other team" vote; that sounds like a messy can of worms.
But with replays, I can eat my loss, then send the replay off to the Powers That Be with a note to the effect of "Watch what IAmACheater does at 15:23." Then, at least, I have a better hope of getting the exploit patched and bringing Swift Justice from Above down on the exploiter.
. . . I can dream, right?