Or so it appears.
I still see other possibilities.
If Mueller is secret good guy (or controlled, flipped bad guy), the sexual assault allegations could be a Deep State "wrap-up smear" just like Kavanaugh. Maybe bad guys just figured out Mueller isn't their guy and are now desperate to shut him down, so wrap-up smear. (would be a good lead-in for Kavanaugh accuser prosecution. Hey, they did to Mueller, so…)
In that situation Whitey may have been killed by the cabal, not Mueller & Team.
Could've been a cooperating witness.
Maybe pulled into protective custody.
Etc…