"But .. you're ignoring the statements by Shaffer that he briefed the commission's staff - and when he returned from deployment - he tried to re-brief them but they told him they didn't need the information...."
And it is my understanding that during that 9-11 Commission presentation, Atta did not come up as evidenced in Shaffer's own notes. And by the time he returned from deployment there was no need to re-interview him because the Commission saw what a bogus effort it was.
Well .. if your premis is already established that it was a "bogus effort" .. you have already made up your mind.
On the otherhand, I believe there was no need to re-interview him because the documents had been destroyed - and there was no reason to even bring it up - Gorelick had already successfully CYA'd the issue .. she thought!
The whole 9/11 commission had one goal: IT'S ALL BUSH'S FAULT! That was their established premis, and no other information was going to be allowed to change their agenda.
If you believe it was bogus .. fine .. I don't believe it was bogus.