Mueller's evidence of Manafort 'tampering' with witnesses is weak
...This looks like more harassment by Mueller in his attempt to extort testimony out of Manafort. It also is counterproductive if Mueller really expects to use Manafort as a witness. It is typical of the overkill Mueller has used against Manafort from the beginning. If Mueller were really concerned about the outreach to the witness, he should have called Manafort's attorney and warned him to stop it, rather than go after Manafort with a howitzer.
I think that the special counsel's allegations of witness tampering are rather ... thin. The FBI agent's declaration in support of the allegations is long on detail about what Manafort and the "Hapsburg Group" did before the elections and short on information about the tampering allegation itself. Drill down into the exhibits and you will see that only one, Exhibit N, is evidence of communications between Manafort and the witnesses he is alleged to have contacted in a tampering effort.
Study that exhibit and you will see that Manafort was successful in speaking to one witness (Person D1) for exactly 1 minute and 24 seconds. He attempted three other phone calls that did not connect and he sent two WhatsApp messages—one a link to an article describing his indictment and the other saying "we should talk." When asked about the contents of the conversation with Manafort, according to paragraph 14 of the FBI declaration, Person D1 said that "Manafort stated that he wanted to give Person D1 a heads-up about Hapsburg" and "D1 immediately ended the call because he was concerned about the outreach."
And that's it. Really. The other part of the allegation is that someone else, Person A, reached out to Person D2 and told D2, in a series of texts that "P" (presumably Paul Manafort) was trying to reach D1 to brief him and that "Basically P wants to give him a quick summary that he says to everybody (which is true) that our friend never lobbied in the US, and the purpose of the program was EU." A month later, Person A reached out directly to D1.
The key to all this is Person D1's perception. He says he thinks that Manafort was trying to suborn his perjury because he knew that the Hapsburg Group had, in fact, lobbied in the United States. Person D2 likewise seemed to think that Manafort was trying to send a message to members of the Hapsburg Group.
But direct evidence against Manafort is almost nonexistent. Saying "we should talk" and "I want to give you an update" or a "heads-up" is hardly the stuff that true witness-tampering charges are made of. And, more to the point, if the entire conversation in which Manfort participated lasted for less than a minute and a half, he'd have to be a very, very fast talker to have accomplished tampering.