Rosenstein, in the bizzaro world of DC Politics and the DOJ/FBI, is the ONLY person to have appointed Mueller, and the only person with control over him.
Of course, that’s after Jeff Sessions absolved himself of any responsibility over this deep state soap-opera.
Kabuki theatre. Rosenstein and Sesions bait the President into firing Comey, then Rosenstein immediately appoints Comey’s BFF to investigate the President for alleged obstruction of justice because he fired Comey on the recommendation of Rosenstein and Comey. If this was fiction it would never sell because the set-up is so transparent that it lacks suspense.