Commentary tracks to documentaries

Following up on yesterday's post, when the director and producer did their commentary track, they were expecting Orny Adams to do one. He didn't, although there's a short film called "Where Is Orny Now?" (iirc) among the DVD's special features. Documentary theorists sometimes worry about the imbalance of power between documentarians and their subjects. Giving unhappy subjects the chance to do commentary tracks would seem to be a way to reduce this imbalance and to introduce "oppositional voices," as theory would put it. But I don't know any instance of this. Seinfeld and his friend Colin Quinn (who appears in the film) do a commentary track on the Comedian DVD, but they're happy with the film, as far as I can tell. The two high school basketball players who are followed in Hoop Dreams do a commentary track on the DVD to that film, but they likewise express no complaints about the film. The only "oppositional" commentary tracks by a film's subject that I know of are to mockumentaries, where sometimes the main characters will do a commentary track in character. The examples I've heard are on the DVDs of This Is Spinal Tap and Nothing So Strange.