I highly recommend the site, http://www.hardllaw.net/Truth_About_Bowling.html
For Example note the following from the link above.
2. NRA and the Reaction To Tragedy. A major theme in Bowling is that NRA is callous toward slayings. In order to make this theme fit the facts, however, Bowling repeatedly distorts the evidence. A. Columbine Shooting/Denver NRA Meeting. Bowling portrays this with the following sequence: Weeping children outside Columbine; Cut to Charlton Heston holding a musket and proclaiming "I have only five words for you: 'from my cold, dead, hands'"; Cut to billboard advertising the meeting, while Moore intones "Just ten days after the Columbine killings, despite the pleas of a community in mourning, Charlton Heston came to Denver and held a large pro-gun rally for the National Rifle Association;" Cut to Heston (supposedly) continuing speech... "I have a message from the Mayor, Mr. Wellington Webb, the Mayor of Denver. He sent me this; it says 'don't come here. We don't want you here.' I say to the Mayor this is our country, as Americans we're free to travel wherever we want in our broad land. Don't come here? We're already here!" The portrayal is one of an arrogant protest in response to the deaths -- or, as one reviewer put it, "it seemed that Charlton Heston and others rushed to Littleton to hold rallies and demonstrations directly after the tragedy." The portrayal is in fact false.