Time will tell, maybe they're both fighting it out for something we arent aware of as of yet, maybe all this has nothing to do with georgia, maybe its the American vs Russian war on Georgian soil, Russia trying to break the Georgian American alliance, by proving to the georgians no one will be there for there aid now that they bombed the living shit out of them, and its turning out to be true.
but then again i wont single out the other criteria i mentioned either, anything is plausible.
theres many reasons as to why this fight mightve broke out, you have to take into consideration when you think of it on a larger scale, Georgia is an american ally, a country where the US could use to deploy its Missile shield in the future like it was trying to do in Poland, and the Russians might've used these means to stand in the face of the U.S and show them, things wont go down as they please.
but again time will tell, everything eventually comes out