Notice that the second sentence contains a different rationale from the one offered in the first. In the second sentence, Hayden says that officials ordered the taping to ensure that the transcripts of the interrogations were accurate. Perhaps. But in the first, he cryptically refers to an "internal check" on an inchoate interrogation program -- one of dubious legality -- that began with Abu Zubaydah's March 2002 capture.
What might that mean? On one reading, the tapes are there to ensure that the interrogators didn't go beyond what the administration was authorizing, as a check on the interrogators themselves. Recording, then, has the added virtue of (if you'll forgive the vulgarity) covering the CIA's ass, a hallmark of George Tenet's tenure as CIA director: they'd be able to say in internal administration discussions that Interrogator X didn't do a thing that John Yoo, Jay Bybee et. al. didn't say they can do. Yesterday's Newsweek report from Mike Isikoff and Mark Hosenball provided that explanation.
They also provide another, one that Kevin Whitelaw runs down in U.S. News, that the tapes were made "in part to document [Abu Zubaydah's] medical condition...
During the operation to capture him in 2002, Zubaydah was shot multiple times, including in the groin, and was treated by CIA medics.
"There were concerns that there be a record of his medical treatment and condition in the event that he died," says one intelligence official."
Though Hayden mentions -- without elaboration -- that Abu Zubaydah was "seriously wounded in a firefight," he doesn't link the videotaping to Abu Zubaydah's health. It's not inconceivable that the health issues prompted the videotaping: after all, the last thing CIA wants in a torture chamber is a dead body, as an interrogation of dubious legality could become a potential homicide. Documenting that the CIA didn't kill Abu Zubaydah makes a certain amount of sense -- certainly on the Cover Your Ass Principle.
But that still isn't the explanation that Hayden offered. Hayden, of course, wasn't part of CIA in 2002, and only found out about the tapes in 2006, when he was principle deputy director of national intelligence.
A real answer, if it ever comes, is going to have to come from George Tenet or one of his subordinates -- maybe even someone who was in the chamber with Abu Zubaydah and made the decision on the spot. (That, of course, wouldn't explain why al-Nashiri's interrogation was videotaped, but still.) And that answer is surely only going to come when someone's hand is on top of a Bible.