The SCO suspects this.
Greg Andres (SCO): "Judge, throughout the interviews with Mr. Manafort and some of the issues we discuss today, you see that he constantly either minimizes the information he has about the administration or any contact with the administration. So there is an issue whether or not during his cooperation he's communicating with ________________, or providing information about the questions or other things that are happening and special counsel's investigation, whether he's sharing that with other people." pp. 126-127.
They didn't share what they knew. He made a proffer that checked out with evidence they already had. He then walked it back and got caught. He could just share what they were probing and report back the questions that were asked. This seems to be the standard operating procedure for the Trumpers which are then relayed to the Media and spun, which is why we have so many garbage stories out there where people need to read with a discerning eye to find the truth of the matter.
Basically, I think Manafort was essentially dealt with at a distance while he was on trial, but after the plea deal the WH reached out through intermediaries and he thought he had an angle to play. He has no angle to play. He's just headed to jail. The SCO wants nothing to do with him. He sat there for the entire 4 hour hearing. What was going through his head? The only thing that would give his life meaning at this point would be to divulge the full truth through his lawyers to the SCO. They may or may not use it, but a full confession would do him a world of good. There is absolutely no way he is getting a pardon after that transcript release.