Sounds like Zelikow was more concerned about selling his public myth than about doing a sound investigation. He doesn't say what they did if they could not find reliable corroborating evidence.

"Specifically, the NBC News analysis shows 441 of the more than 1,700 footnotes in the Commission’s Final Report refer to the CIA interrogations. Moreover, most of the information in Chapters 5, 6 and 7 of the Report came from the interrogations. Those chapters cover the initial planning for the attack, the assembling of terrorist cells, and the arrival of the hijackers in the U.S. In total, the Commission relied on more than 100 interrogation reports produced by the CIA."

About five weeks ago we wrote:
"Most of the endnotes to the report indicate the sources of information contained in the main body of the text. Of the 132 endnotes for Chapter 5, 83 of them cite detainee interrogations as a source of information contained in the report. Of the 192 endnotes for Chapter 7, 89 cite interrogations. [9/11 Commission, 7/24/2004, pp. 488-499, 513-533] The interrogation of 9/11 mastermind Khalid Shaikh Mohammed (KSM) is mentioned as a source 211 times. [9/11 Commission, 7/24/2004] He was repeatedly waterboarded and tortured (see Shortly After March 1, 2003) and it will later be reported that up to 90 percent of the information obtained from his interrogations may be unreliable (see August 6, 2007). Interestingly, the 9/11 Commission sometimes seems to prefer KSM’s testimony over other sources. For instance, in 2003 the 9/11 Congressional Inquiry reported that the CIA learned in 1996 that KSM and bin Laden traveled together to a foreign country in 1995, suggesting close ties between them (see 1996). But the 9/11 Commission will ignore this and instead claim, based on KSM’s interrogation, that KSM and bin Laden had no contact between 1989 and late 1996. [US Congress, 7/24/2003; 9/11 Commission, 7/24/2004, pp. 148-148, 489 The interrogations of al-Qaeda leader Khallad bin Attash are used as a source 74 times, 9/11 hijacker associate Ramzi bin al-Shibh, 68 times, al-Qaeda leader Abd al-Rahim al-Nashiri, 14 times, al-Qaeda leader Hambali, 13 times, and and a generic “interrogation[s] of detainee” is used as a source 57 times. [9/11 Commission,7/24/200] "
http://www.cooperativeresearch.org/context.jsp?item=aafter0104commission...

The spin at the moment is that the 9/11 CR is based on waterboarded BS, but is accurate anyway. I really doubt that will hold with any degree of conviction for long.