Tinfoil hat notwithstanding (I've not seen the video and have no intention of watching it at this time), the mere fact that a segment of the population could even consider that a conspiracy surrounding this tragedy could exist, supported by the government, upheld by the government, and underwritten by the government, is staggering all by itself.
The truther thing is yet another WTF? that's rather old hat right now, but I think it's seriously an issue that people have so little trust and faith in government as to suggest this kind of thing.
Don't get me wrong -- I'm definitely one of those who believes the government has a role that they've long since forgotten about and I wouldn't trust a bureaucrat as far as I could throw him/her.
It's really just an indictment of how pissed off and distrustful we are.