Michael Moore wouldn't know a "truth" if it bit him on his extra-wide butt. He is the king of deliberate lies and falsehoods, and his propaganda screed "Bowling For Columbine" should not be nominated for a Best Documentary Oscar, not only because it's a piece of excrement but also because it's a giant wad of lies. You probably know many of them already, but here are a few you might not have known about:
http://www.hardylaw.net/Truth_About_Bowling.html