Yes, of course, but there are some things that are pretty much undeniable.
For example, in BfC, Moore showed Charlton Heston giving a speech for NRA in Denver (near Columbine), saying how it was callous and such, and that the NRA should have gone elsewhere, but they actually had to hold the meeting in accordance with some New York law and whatnot, and they in fact cut down the big event to just that one meeting, he also put in a clip of Heston saying "from my cold, dead hands", which was actually from a speech a year later in Charlotte, NC, but they edited it (cutting between scenes) in such a way to make it seem that it was in fact the same speech, but you will notice that Heston's tie and suit change. You could argue that would tip everyone off, but it just seems edited to hide that and give you the impression that it was the wrong thing to do and they had not feelings for what had happened. They also did the same thing with another Heston speech in the town where the little girl was killed by a boy in her class, Moore made it seem like Heston came in days after the incident, when in fact he came in about 9 months later, yet Moore just lets you assume it was another callous NRA event. Anyway, there was more, but that's what I can remember off the top of my head.
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