An exchange seems more of like a deal than a payback. I think Q is telling us that they flipped a high ranking cabal spy equivalent in value to Stanislav Lunev. Could be Snowden.
Yes you're right. A payback to clowns makes sense together with an exchange with the Russians. Perhaps as another anon suggested Snowden for Lunev exchange. Would also imply that Lunev was recruited by clowns after originally defecting.
I'm sure the clowns attempt to corrupt every defector. But I doubt the original talks pre-defection would have gone over it. I suspect your average defector would first arrive into the US under the assumption that they're now on team USA. It would seem like a whole new conversation would need to be had about betraying US to the cabal. Makes sense that most would follow through considering they've already once defected with the same clown handlers. But b4 the exchange it's just a speculation that secondary defection succeeded. With the above referenced exchange assumption, it's deduced.