The problem with Moore, though, is that he takes something that is CLEARLY fictionalized, piecing together elements (selected portions of statements, for example) that don't go together, taking things out of context, or creating imaginary contexts for things, and tries to pass it off as a documentary. If I cited material of the type that Moore creates in any of my own research, I would become the laughing stock of the scholarly world. Looking at various points of view is very important, of course, but the only thing that Moore does in his fictional documentaries is misrepresent views.
Moore's movies are on the scholarly level of something like the National Enquirer (a trashy gossip magazine--aliens, two-headed people, Saddam and Osama getting married, and stuff like that, for those of you not familiar with the lesser elements of American society). It can be amusing, but only because of how ridiculously ludicrous it all is, and it's not going to add anything substantive to the debate for either side of the issue. Even a few errors can discredit a source, and Moore's movies are distortions and misrepresentations from beginning to end. Even if he makes a good point here and there, Moore's movies are not the kind of sources that anyone who wants to maintain credibility should be citing.
Unfortunately, Moore chooses to do anything he can to provoke an emotional response. Instead of presenting the reality of the situation (including the things people REALLY said, instead of his hack job editing of it into something completely different) and then giving his interpretation of it, he presents something that is grossly (and very clearly) distorted to support his agenda. Obviously there is going to be some spin in just about any political presentation, and especially in satire, but Moore goes waaaaaaaaaaaaaaaaay over the line at which even normal scholarly ethics would dictate a stop.
Rather than "Bowling for Columbine," it should be called "Straw Man for Columbine." What Moore presents and then attempts to knock down is fictional, a proverbial "straw man." If he's going to oppose something, he should at least oppose its reality, not something that only exists in his fantasy world. Whether he's a liar (misrepresented on purpose), apathetic about the truth (didn't do careful work), or just plain stupid (tried his best but screwed it up anyway), the result is the same, and it doesn't flatter the anti-gun crowd any more than the pro gun rights crowd.
Of course, Moore is nothing even close to being a scholar (professional or amateur), and has no real qualifications and has shown no evidence in his work that he can be trusted to do careful, honest research and present reliable material. I guess I shouldn't expect him to HAVE scholarly ethics, then. He can't do real scholarly work, so he creates propaganda films and tries to pass them off as documentaries. That they have been accepted as such by many in the Academy, etc., is nothing more than a very sad commentary on the state of those organizations.