I've only watched the first few minutes of this film so I'm not endorsing it, but please enjoy the Dickster saying that there's no evidence OBL was behind the attack.
Some may argue that Cheney says OBL was not directly involved. The official theory was that he was the leader of the organization which planned, funded, and executed the massacre. More importantly, it was claimed that it went ahead on his say so. Certainly the man who ordered the outrage can be said to be directly involved.