From what I gleamed, the guy that claimed he was Deep Throat was in fact the #2 guy at the FBI, and fed the then-junior reporters the FBI-collected info.
Why? He was ticked off at Nixon because J. Edgar had just died, and Nixon went outside for the new Director, and #2 expected the job.
And Nixon did eventually find out who was feeding the WaPo.
I didn't get either the author or the title, but it must be a very recent release.
I'll speculate and say this is Bradlee's response to that book's publication. I don't recall Bradlee being mentioned during the appearance, but I could have missed that part.
You gleamed that huh?