I met Billy Mitchell briefly in 2015 at the now defunct Museum of Pinball in Banning, CA. He was promoting the world record for most people playing pinball simultaneously we participated in. I asked him about his depiction in the documentary and he replied something like "it's all true" with a lot of smirk and theatrical swagger. I got the impression he was a ruthless self promoter in all things he does, with his sauce business and his public ego and all the theater around the videogame records and most of what he was doing was all kayfabe as a heel, to use a wrestling term.
Later he handed off a high level game of Ms. Pacman he was playing to me in good fun. He really is very good at the games. (I didn't last long). People are complicated.