That guy is full of shit. He misrepresents facts and takes words out of context to construct a specious argument.
In particular, he takes quotes from fire engineering magazine way out of context, knowing that most people don't read such specialty publications. Well I do happen to read Fire Engineering MAgazine. The article he quotes from, while critical of the government investigation, agrees with the commonly accepted theory that fire brought down the towers. Not only that but the Technical Editor of FEM said so explicitly on national television and ridiculed this particular conspiracy theory.
There was enough steel left over from the site for NIST to conduct tests of the steel. The report was realeased earlier this year, and is widely accepted by structural engineers and fire investigators.
The theory that fire couldn't have brought the towers and building 7 down, and that explosives must be responsible is ludicrous. Steel doesn't have to melt for the building to collapse. It loses its strength well below the melting point.
Ask yourself this simple question: why do they put fireproofing on structural steel? Because steel is vulnerable to fire. What happened on 9-11? A bigass fire.
It's true that steel buildings haven't collapsed due to fire before. That doesn't mean it's impossible. We didn't know everything about how materials behave in fire in 2001. We don't know it all today, either.