Still don't know whether Sessions' recusal was idiocy, stratagem, or necessary for political appearances / to preserve prosecutorial independence.
Also, Mueller and Comey have been friends for a long time; several of the top people,including Mueller and Comey were deeply involved in Uranium One; and in addition to one Federal Judge who had to recuse themselves, there is another Fed Judge, a last-minute Obama appointee who served on the Harvard Law Review with Obama (and who blocked one of Trumps EOs), who magically got assigned one of the earlier dirty cases, and one of the related new cases -- I think his last name is Chang.
There have been disputes as to whether they have been friends. They have had a working relationships in the past. That alone would seem to me to be a reason Mueller should have turned down SC. Lawyer pundits suggest he can recuse himself for any part of the investigation that involves Comey. That still doesn't look good though.
From the reports I've read, it looks Mueller will have a damaged reputation because many of these abuses occurred and the bad actors worked on his watch at FBI. I guess we will find out soon enough.