It is, and it's a violation of the law.
"...personal relationship with any person substantially involved in the conduct that is the subject of the investigation or prosecution." [28 CFR 45.2]
Either Rosentein and Mueller aren't familiar with the Code of Federal Regulations as it applies to Superfluous Prosecutors or they both are ignoring the law for some other purpose.
Where's Trump's lawyer on this? Where are the congressional republicans? They should insist that Mueller recuse himself---or better yet, shut down the SP.
Because something about it stinks.