In one of the film's oft repeated moments, Dunn attempts to interview Mayhem's Necrobutcher at a festival, who clearly appears aggravated at the suggestion that black metal is not as popular as it once was. In 2015, Dunn would interview Necrobutcher again for his Metal Evolution series' "Extreme Metal" episode about the same subject, with a considerably more laid-back Necrobutcher admitting that Dunn's point about black metal being "fractured" to a more melodic and a rawer contingent is a valid one.
The 21 year sentence in Norway is called "life sentence", so the life sentence in Norway is 21 years.