This is a classic example of something I mentioned a while ago: the inability of truthers to incorporate debunkers into their world view at any level. Particularly difficult for them to acknowledge is the pronounced asymmetry by which truthers are known to have converted to the debunker side, but few if any debunkers have converted to the truther side. In fact, there seems to be a three-step progression: Uninformed -> truther -> informed understanding that 9/11 was carried out by al-Qaeda, where steps can be missed out but the progression is only one way. If the truthers' views had any merit, we might see a significant proportion of moves the other way, from active debunker to truther; yet, it seems, we rarely or never do. So we have bill smith, in active denial, refusing to believe in reality because it can't be reconciled to his mistaken views, claiming that converted truthers were never true Scotsmen truthers in the first place, or SteveAustin, claiming that debunkers are paid CIA disinformation agents; simply because their world view cannot admit of the possibility that intelligent and informed people could disagree with them. That should be one of their biggest danger signs, and it's one they have to work extremely hard to rationalise away.
Dave