It's highly possible that there is NO Deep Throat and Woodward just used the "unnamed source" bit to cover for stuff that he may have made up and he got lucky that a part of the W&B writings led to end result.
Woodward could have just ran a list of Nixon DOJ names and decided that when one of them dies, he'll just claim that person as Deep Throat....against no defense.
Sounds like Woodward's M-O.
Remember CIA boss William Casey deathbed confession to Woodward?
It was a bombshell until, Woodward was asked to sketch out Casey's hotel room.
Woodward couldn't do it.
FWIW -- I believe Woodward made up the whole thing.
I've been saying that for years... there is no Deep Throat. Woodward made some inferences based on some facts he had, but he knew the WaPo wouldn't publish his article based on inferences. So he made up this character, and suddenly his "inferences" became "inside information", and the story got published.
I hate Bill Clinton for the lying and criminality that characterized his administration. Nixon was equally bad, and terrible for the party. I'm not going to give Nixon a pass just because he was ostensibly on my side. It wouldn't suprise me if someone in his administration turned on that "evil old man" as x41 called him.
As for Woodward, if there is no Deep Throat then he should start working for the psychic friends network. The accuracy of his "guesswork" is phenomenal.