Well, he looked into Hillary’s emails and might have felt compromised and (a) wanted out of dubious investigations or (b) objected to this one and complained to a see-no-such-evil Mueller.
As chief of the FBI’s counterespionage section last year, he helped oversee the FBI’s investigation into Hillary Clinton’s use of a private email server, and he took part in the FBI interview of the Democratic presidential candidate.
Who knows? I sure don’t.
Blithe Spirit 