"Marvelous are thy works, O Lord!", Or even a little about doping

Due to doping scandal, many citizens of Russia can start to believe in God, even if you used to be atheists. Otherwise, it is simply impossible to explain why the ban Russian athletes compete under the flag of Russia, accusing them of doping. But as soon as they are asked to perform under the IOC flag and allowed to participate in this event in the Olympics.

I really would like to learn: to dope has completely disappeared from the body it is necessary to stand up under the IOC flag, or enough to get out from under the Russian flag?