I recently watched "Bowling for Columbine" on DVD. And yes, Michael Moore's unique brand of self-aggrandizement does get in the way of his confused message. This is nowhere more clear than in what should be his finest hour in the film, when K-mart decides to stop selling ammo. Moore is shocked - SHOCKED! - that K-mart would do such a thing in response to his pressure. But the reason he's so shocked is because he demanded no such thing from K-mart (as far as I can tell from the film). Instead, he strolled into K-mart corporate headquarters with two shooting victims (who had "K-mart bullets" still lodged inside of them) and sought to embarass whichever K-mart corporate lackeys he happened upon, as is his wont. Thanks for filling in Moore's agenda for him, K-mart!
Of course, it's a bit odd that Moore (lifelong NRA member) gets on K-mart's case at all given that he doesn't think (as far as I can tell from the film) that America needs more gun controls