Mueller and Comey have been butt buddies for decades.
Mueller has an irreconcilable conflict of interest in investigating ANYTHING that involved James Comey - which every aspect of this year and a half long charley foxtrot is tainted with.

Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good ...