The different ways Dungeons and Dragons can be played is definitely reflected in this documentary. There is one DM that always wore a hat, can't remember his name, but his methods were very unorthodox, when you see it you'll understand because he DM the games based on his mood - should I kill all the characters today or not? and that was frightening as a player to know especially if you took years building up a character.
I know the guy you're talking about. I didn't like his style one bit. If my character lives or dies should be based on the mood of the DM but my own character choices. Doing it the way he did it is totally unfair.
I saw this thread awhile ago and looked for the documentary. After I saw it I forgot to return and put a review. In all honesty it was a bit dry. I was expecting to hear more about how Dungeon Masters plan games or their styles. Their thoughts on different game and things like that but it was really about the lives of the Dungeon Masters. Nothing was wrong with them focusing on that I just was expecting something different.