Just in case you have to seen it yet: there is an interview with a Durtch controlled demolition expert, Danny Jowenko, on youtube. He is very sure it was controlled demolition, but considers the possibility that it was decided ad hoc by Silverstein to get the terrorism insurance money for the building:http://www.youtube.com/watch?v=k3DRhwRN06I
Link is to the first of three parts.
But: it kind of opens an escape path for the government: they could say, yes, there was a lie (Breaking News!), it concerns the cover-up of Silverstein's insurance crime, which we did to have a clear-cut picture as far as good guys / bad guys (USA/others) is concerned.
One more reason to keep researching the Pentagon-case.