They seem to have a whole system set up, but most of it is fairly common sense apart from a particular mechanic:
The "Lebanon" means that all raid members (except for the Checker) Press the "go to the battlefield" and immediately press alt + f4 (or any macro that you immediately throw out the game). Thus on the one hand, you went to the ratings battle, and the other - on the very field of battle you progruzilis. If you close the game in this way you will not come online until the game is on the battlefield (which will monitor checker) - you will not remove personal rating.
Apparently if you alt+f4 during the loading screen, the result of the game will not affect your rating.
Is this a known exploit? I've never heard of it before myself. If this holds up it deserves immediate attention.