federal appointees [NOEL FRANCISCO] can't participate in matters related to their former employers and clients for two years.
Walter Shaub, who ran the Office of Government Ethics and is now a CNN contributor, wrote on Twitter that Francisco can't take over the probe "unless the White House has secretly issued a waiver" of an executive order that Trump signed last year.
http://www.weny.com/story/39162367/what-happens-to-the-russia-investigation-if-rosenstein-is-ousted