I haven't researched the actual chronology, but I think Emmert's tenure at LSU overlapped with Saban's tenure at LSU. If so, than, at least technically, Saban reported to Emmert. Thus, Emmert might have to give serious consideration to recusing himself from the investigation of the allegations pertaining to D.J. Fluker. Whatever the NCAA does, USCw will be watching closely, and its AD, Pat Haden, isn't shy about expressing his opinion publicly.
Emmert hired Nick. He has been president of UConn, LSU and Washington and has worked at many other schools. Emmert's NCAA doesn't enforce the rules on anybody. Why should he recuse himself?