Errol Morris discusses advertising and his recent documentary, the Fog of War in this interview.

HuffPost: But there’s certainly been criticism, especially with McNamara, that you may not have pushed hard enough.
Morris: In truth, I wish I had done something like that when he went on and on about the Gulf of Tonkin incidents. Didn’t we try to provoke them? A number of people have criticized me and the movie for giving a false impression or what they consider to be a false impression of those events.
HuffPost: You and Eric Alterman had a conflict about this issue in the film, about footage that may or may have existed showing McNamara discussing secret intercepts regarding the Gulf of Tonkin.
Morris: Right. Alterman just engaged in hand-waving. It’s sort of, “You’re not a historian so why should I listen to you?” I’m not a big enthusiast of that kind of argument. It’s like in Mr. Death, Fred Leuchter, the Holocaust denier, has a degree from BU in history. Does that mean that his historical views are more valid? No.
I’m always puzzled when people ask if a film is true or false. Fog of War, true or false? Fahrenheit 911, true or false? Sorrow and Pity, true or false? Isn’t what interests us about documentary film, that there is a claim that relates to the world and hence does have truth value? You can think about things that are said by people and think, is this true, is this false, what is this?