The Michael Moore version of history! Big fat and stupid!
That’s according to Special Advisor to the US National Security Council, Richard Clarke, in his testimony to Congress about the roll he played after 9/11. He specifically said he cleared the 747 containing members of the bin Laden family to leave the US while all other aircraft were grounded. Members of the bin Laden family on the plane did get a very superficial questioning by the FBI before the plane departed.