They’re just pulling something out of their asses to rationalize / try to justify a “do-over” on the whole Russia investigation. “Our guy’s retarded. We want to do it again.”
My response to “Our guy’s retarded. We want to do it again” would be something like “Your all retarded (and crooked), and NO do overs”.
Mueller didn’t have anything to do with the report. And, it sounded like it... this was all new information prepared for him by Andrew Weissman.
Mueller was a front man purposed to lend creditability. Backfire, but a well deserved one.