OMG.

I'm NOT TALKING about him still giving them information from his time with NSA and CIA. Nowhere did I say that. If these are the interpretive skills you had during you "26 year SIGINT" career I'm concerned for our national security!
I SAID...essentially....that Snowden's CREDENTIALS are of value to the Russians. And they would have every reason to want to employ those skills and develop them further in service of Russia. He would have been able to predict how the NSA would change and upgrade it's protocols, software and hardware as a response to the security breach. He would have had a better idea than most Russian intelligence specialists about how to hack American systems. And with Russian education and training over the past 10 years he would make a terrific consultant building upon the same work he did in the U.S. albeit in whatever angle the Russians saw fit.
The opposite has also happened. Former Russian intelligence folks have been employed by the west in generally the same work they did in Russia.