Smilin' Dan Rather
Apparently, the reason Dan is angry is that he feels that CBS didn't do a good enough job whitewashing Dan's responsibility for that whole fake document mess in a story that CBS, specifically Dan, broadcast about President Bush's somewhat undistinguished military service. The documents were fake. Everybody says so. The consensus is also that a good reporter would have known better.
Dan, who apparently is still claiming the story is true, avoided taking the fall for this Big Screw-up ("BS" in journalism circles) at the time. Three other CBS employees got fired. But Teflon Dan kept the big anchor chair. Though, as time went by, the incident was not forgotten, and more and more people seemed to openly blame him for the fiasco, as well as his failure to take responsibility.
Jim Lehrer once said, many years ago, "I'm responsible for everything that comes out of my mouth." That is what I expect to hear from a news anchor. But, with the exception of Mr. Lehrer, those days are over. Dan apparently feels exactly the opposite.
Back in 1981 when Walter Conkite was retiring, there was a big discussion on whether Dan Rather or Roger Mudd would succeed him as CBS News Anchor. Mudd seemed more substantial, but Rather was more exciting, having done lots of Viet Nam coverage and challenging President Nixon at press conferences. Rather won and Mudd, and CBS, lost.