While W. Mark Felt’s role as Deep Throat should forever be appreciated for exposing the coverup of the Watergate breakins http://www.democracynow.org/article.pl?sid=05/06/02/1445247 , the other side of his legacy is that he was also a Deep Threat http://www.democracynow.org/article.pl?sid=05/06/02/1445253 . His COINTELPRO operations show he was a burglar who blew the whistle on other burglars.
Yup, IMO he was just pissed at Nixon for appointing a croney as director, bypassing Felt who was Hoover's number 1. A quintessential Beltway dopeslap.