Is the FBI Covering Mueller's Ass?

I believe they are, and over at the American Thinker, Daniel Sobieski is suggesting that is plausible.
Is the FBI Raiding Whistleblowers' Homes to Protect Robert Mueller?
When the FBI was tasked with investigating the IRS for it's behavior toward conservative non-profit organizations, Robert Mueller was touted an impartial leader that could be counted on to solve the riddle. Only problem was there was no riddle and the FBI fucked up the investigation, yielding no findings of fault. No findings of fault where it was plain that program was direct by the White House. That President, probably was not a co-conspirator in a legal sense, they rarely are, but there were high level subordinates who escaped prosecution via Mueller's intentionally inept backstop coverage.
When the FBI was asked to look into Uranium One, same guy, same result.
Now, we might take from this that Robert Mueller is inept as in investigation manager. It certainly seems as if there is no case of significance in the Russia collusion investigation. I am inclined to believe that he is a skilled man, who successfully protected both President Obama and Secretary Clinton. Now he is trying to build a case against President Trump where the facts point to the guilt of his own benefactors.
In this article, the FBI recently server search warrants on an informant who testified before Congress in the Uranium One investigation. The facts are already testified to, what in the world could they have been looking for, the potential of Mueller eviscerating information is a serious possibility.
Like with the FISA warrants signed to spy on Trump, what judge approves such things?