The Threat: How the FBI Protects America in the Age of Terror and Trump by Andrew G. McCabe:
Among all his odd claims, one stood out as being especially dubious. He said, as he had said during our phone conversation earlier that day, We’ve had so many FBI people calling us, sending us messages to say they’re so glad the director is gone.
Who would do that? Who in the Bureau would send a message to the White House about something of this nature? It was not beyond the realm of the possible—there had been so many leaks in the months building up to this point. But for anyone in the Bureau to make or maintain contact with people in the White House would be unambiguously inappropriate—an absolute violation of the White House contacts policy. But the president kept saying it was happening.