They already knew Burkett was a nut! Everybody in the media admitted as much -- including the Boston Globe, for cryin' out loud. Burkett's been trying to retail this story for five years!
Somebody else gave Rather the courage of his own convictions to run with the story -- the "unimpeachable source". Because nobody ever would've mistaken Burkett for such a title.
WHO is the "unimpeachable source"? Ben Barnes? Max Cleland? Robin Rather? Terry McAuliffe? John Kerry, himself?
From the CBS website::
CBS had not previously revealed who provided the documents or how they were obtained.
Burkett has previously alleged that in 1997 he witnessed allies of then-Gov. Bush discussing the destruction of Guard files that might embarrass Mr. Bush, who was considering a run for the presidency. Bush aides have denied the charge.
In the statement, CBS said: "Burkett originally said he obtained the documents from another former Guardsman. Now he says he got them from a different source whose connection to the documents and identity CBS News has been unable to verify to this point."