I would love for Barr to fire a warning shot towards Mueller.
“I trust Bob will use good judgement in speaking only to the facts and conclusions as detailed in the report HE issued. If he strays or speculates on matters outside of those he was charged to investigate the DOJ will take action and respond accordingly. If he had something to say he had his chance to do it in the report.”
Barr did make a statement, almost exactly what you wrote. I think it was during his Alaska interview.