Blanchard's report is irrelevant -- he basically says it doesn't look like a standard controlled demolition. He also cites undisclosed evidence and asks us to take his word.  

Greening correctly assumes that energy is transmitted upward into the 15 story block.  How could Bazant not do that?  Greening concludes that a self-sustaining collapse is possible, like you say.  I can't refute that now but Gordon Ross claims he has. I will respond later to the extent I can. Greening doesn't say how long the collapse would take.  He begins with an unrealistic assumption that a 15-story block free-fell symmetrically over 3 meters.