He said that's why he went' public, because "he does not want to disappear". He sat on the information for 3 years because he didn't trust Sessions. He gave the Justice department the information after Barr was named Atty General. And now he's going public, that he has already given the Justice department everything he knows.
He finally realized that Struck-stroke was just using him and Barr may get it all out. Some subjects have gone back to the FBI/DOJ to “amend” their statements(because they lied originally).