"Manafort himself was later found to have given a close associate, allegedly a Russian spy, internal Trump campaign polling data in August 2016 which eventually made its way to Russian intelligence services. "
The route of the polling data is obvious. Of course it eventually made its way to Russian intelligence services. Unfortunately, That was not the conclusion of the Mueller report, that claimed that the trail ran cold and that they were not definitively able to establish where it went.
Could the FBI and various intelligence services not figure it out? My question has been, did Mueller base the trail-gone-cold conclusion on input from Special Agent in Charge (SAC) of the FBI Counterintelligence Division in New York, Charles McGonigal? McGonigal is now serving a prison sentence for taking bribes from… Russian oligarch Oleg Deripaska.