More on this topic from @RickMycroft:
FWIW, I guess. Some speculation, but if the Russian intelligence services work much like our own (and like we know the Soviet’s did), then all of this is very plausible.
Some of our uncertainty here is predicated on how these sorts of operations work so we often can’t know what they were until you hit a certain distance from said event (here in the US) or when a regime changes (like when the Soviet Union ended and their archives opened up for a period).
