What's great about documentary genre, it seems to me, is that it can be experimental filmmaking. You have a license to do a lot of diverse things under the umbrella of "documentary."
Errol MorrisYou can talk about a caption underneath a photograph being true or false, because there is a linguistic element. You can claim that a photograph is a picture of a horse or a cow, but it is the sentence that expresses the claim, which is true or false, not the photograph.
Errol Morris