Meanwhile, the RF air force has decided that it is ok to down US drones in international waters. I wonder what may happen next.
No one shot him down, they just pissed on kerosene with a nearby flying plane and he himself fell. 
The reason why it is not a good idea (and against regulation) to fly without one's transponder activated is that other planes won't know you are there. It must have been the case that the Russian planes needed to do an emergency fuel dump and simply didn't notice the drone ;^ The only lives which were put at risk were Russian ones and those availing of civil aviation. Anyway, shit happens.