My wife will look at a set of data, come up with an idea for how they fit together, and go with that. She is not good at searching out reasons why her identified hypothesis might be wrong. Killtown seems to have this characteristic, but a million times moreso.
Also I need to add that my wife has significant strengths to compensate for this shortcoming - she's an "action" person who gets things done, and is good at reading people and with relationships. I don't know much about Killtown, but he doesn't seem to have these qualities.
He finds a tenuous explanation that could possibly tie any event together with his obsession, looks for any facts which could be used to support it, but can't fathom that it's also his responsibility to find reasons why that link might be wrong. I really think he believes this stuff, and it's a characteristic of some kind of mental disorder.
But I also think he's an asset to our side. Any rational person who comes across the 9/11 CT stuff and then finds Killtown's rants will immediately see the problem with the way they come to conclusions. Sure, the hardcore CT nuts feed off it, but they're lost souls anyway.