If Mueller decides to investigate Sessions' firing as obstruction, Matt Whitaker is perhaps *the* key witness and therefore must recuse himself from overseeing Mueller. And given that Whitaker was *illegally appointed*, doesn't Mueller have *two* reasons to head to court over it?
2/ A third issue is his prior statements about the probe; a fourth is his conflict with respect to Sam Clovis. The Washington Post has an interesting note on how these issues could end up being addressed (but note the lack of a controlling authority within the executive branch):
3/ "Ethics officials might advise Whitaker his commentary created the appearance of a conflict....If they recommended that he recuse himself and he declined, he could be referred to the DOJ Office of Professional Responsibility, and his license to practice could be put at issue."
