THIS IS NOT LIP SERVICE.
AG Barr stepped WAY out of bureaucratic norms to say this. He knows he will catch HELL for it from the opposition.
Barr had already sent Horowitz back once to redo the investigation, so this is the second go round.
That is the very definition of lip service UNLESS he actually prosecutes someone.
Barr is establishing that he will ultimately determine the facts and ensure the proper conclusions were reached regarding specific actions and criminal liability.
I also think Barr is letting it be known, the facts had better support your conclusions, and if not, there will be hell to pay.