Talk about changing stories in mid-spiel...
I notice, in the story you linked to, that Sen. Frist had an interesting encounter with the Truth Fairy:
“Mr. Clarke has told two entirely different stories under oath,†Frist said in a speech from the Senate floor, alleging that Clarke said in 2002 that the Bush administration actively sought to address the threat posed by al-Qaida before the attacks.
Frist later retreated from directly accusing Clarke of perjury, telling reporters that he personally had no knowledge that there were any discrepancies between Clarke’s two appearances. But he said, “Until you have him under oath both times, you don’t know.â€
I'll just bet he backed off of an implied perjury allegation made on the Senate floor (and therefore on the public record), for crying out loud, especially since he admitted that he had no knowledge to support it. Senators are not immune to civil suits. A suit for character assassination would be a doozy.
Mr. Clarke didn't just fall off the turnip truck. I would be very surprised if he didn't have his own detailed notes of his own testimony on both occasions. I don't doubt that there's a big discrepency between what Mr. Clarke said and what Sen. Frist hopes he said.