I'll do my best to answer your post without facts.
I would assume all of the information gathered before has been speculation based on very strong evidence, As usual, it's what critically thinking humans use to arrive at a judgment before rock solid facts arrive. To my knowledege, we didn't have actual evidence, and still don't simply based on what Deripaska said, but it's another piece of information supporting the actions of Weissman' history as an attorney, and fits perfectly.
What I'm beginning to believe is that Mueller didn't do a hell of a lot of work as special counsel. I'm not even sure he knew all of the evidence "he" gathered was correct, or not. I kinda think he was a figure head.
Edit: For some reason, I have a feeling Mueller was the one who kept the final report from recommending action for obstruction to the House. Of course, he used wording that apparently doesn't say what it says to not recommend impeachment, but you know Weissman was a 100% supporter for impeachment. In fact, based on previous articles, he fully supported going after as many members of the Trump family as he could "legally" incriminate. Whether that's true or not, I don't know, but once again, his prior actions support my comment.
Candidly, if he ends up being professionally smeared due to his incompetence, that's outstanding. The best part is there's a possibility Barr/Durhan may find predicate to review, or open the Hillary e-mail case again. Now if we can get predicate to do the same for the Clinton Foundation, then everything except Benghazi and the IRS fiasco would be investigated by honest to God investigators.