Question: If the explosion was internal, wouldn't the metal from the plane show an outward bend? I haven't been able to find anything that confirms one way or the other which way the blast was going. Have you?
The conspiracy on all of this is quite simple - don't want to freak out the American public so that we'd stop flying for fun. Make it a mechanical problem - ask Richard Clarke - he concluded that before any evidence was given to him. All about re-election and the economy.
According to the documentary, the explosion was internal. When the wall of the fuel tank failed, this caused a stuctural part of the aircraft to fail also. The aircraft started to split a the bottom and it continued to the top behind the cockpit of the aircraft. It literally tore itself apart.
I would be more leary of flying based on what I saw in the documentary than if it was hit by a missile. The documentary basically meant under the same conditions, any 747 or aircraft with the same basic design of the fuel tanks could have the same thing happen to them.