"9-11 families do not by some mythical proxy have all the correct answers..." That's true. They've been given a free pass and considerable access to the media because of their loss. But, as noted above, their loss did not bestow some gift of advanced knowledge upon them. Having said that, McCain appears to be on the verge of a spittle flying rage.
Agreed regardless of whether one agrees with McCain or the 9/11 families represented by these individuals no one in public office should loose their cool especially if this report is correct to the point of having to "encouraged" by security to go back into the building.