Factual error: The interior shots of the Gemini and Apollo Spacecraft show worn and dirty panels, knobs, switches and circuit breakers. The movie most likely used some original cockpit trainers, but in reality the astronauts were flying brand new spacecraft that were spotless.
Factual error: In a scene in 1980, Brian May is teaching everyone the beat for his new song "We Will Rock You." However that song was released in 1977.
Other mistake: Just after signing the contract, you briefly see Stan in his hotel room. The smoke from his cigarette is moving downwards.
Other mistake: During the murder in the stairwell, an old woman opens her apartment door outward, and Varg kicks it shut. Apartment doors always open inward, as did Euronymous' apartment in the same building.
Continuity mistake: When Gotti and Neil are talking with Sammy Bull and Frankie in the night club, Neil's cigar changes position between shots. He is first putting a cigar in his mouth, then in the next shot, the cigar is gone and he begins to raise it to put it back in his mouth. In the next shot, it is instantly back in. (00:21:20)Casual Person