Who cares? All conspiracy theories have to offer are "why do you think?" questions that string together random facts that are either a) ignorant, b) incomplete, c) irrelevant or d) all of the above.
The only proof you need that it wasn't an inside job is the sheer number of people that would have had to be involved in any kind of plot - and the fact none have gone public. That and the fact it is totally bizarre to suggest it was an inside job. Seriously, get a life, people.