Why did they tape this?

It seems as though our "intelligence" officers have destroyed some videos they made of an interrogation. (Why do I suspect that someone has a copy?)
The official story is that the tapes were destroyed to prevent outing the agents involved.
The general speculation is that the tapes were destroyed because the showed the guest of honor, Abu Zubaydah, being tortured.
Another line of thought has it that Mr. Zubaydah implicated some members of the Saudi royal family.
Now, there are enough tangents in this story to teach a graduate Geometry class. There is plenty of time to expound on them.

I do have one question:
Why was the interrogation videotaped?
And if it was, why weren't the videos quietly destroyed when they were no longer useful.
One of the things about the Abu Ghraib scandal was the evidence produced by the soldiers involved. It would seem to be common sense that if you are going to torture a detainee, you do not want a video record. Much has been made about how waterboarding leaves no visable marks on the guest. Why use these "stealth" techniques if you are going to make a video?
Was Genarlow Wilson working for the agency at this time?
HT to ATLmalcontent for this story.
Spell check suggestions for this feature:
atlmalcontent- AT malcontent
Zubaydah- (no spelling suggestions)
Ghraib- Grab, Grail, grain, gray, grabs
waterboarding- weatherboarding
visable- visible, viable
Genarlow- Gnarled, gearbox, generous, general