Revealing mistake: Right before the scene where Freddie meets with the band to try and make amends, he's arguing with that one man in the rain. After he walks away and it's raining only on him and on the pavement. If you look to the right there is no rain coming down on the grass or trees or anything else.
Factual error: In the film, Freddie meets Brian and Roger after a gig. In actuality, the three were friends while in college, after which they shared a flat and Freddie and Roger worked together selling used clothing. Freddie was in another band but was a fan of Smile and his friend was the lead singer Tim. Freddie replaced Tim but John was never in Smile. He joined after the name changed to Queen. Also, when Freddie berates John about his electrical engineer education, that wasn't true. In fact, John Deacon invented the "Deacy" amp which Queen, to this day, still uses.
Continuity mistake: During the "Another one bites the dust" scene, Freddie is given a sheet, which he holds with his left hand, beer in his right. A shot later the beer is gone and the sheet has swapped hands. Then a shot later the bottle reappears in his right hand. He never gives it or has it given back. (01:12:55)Sacha
Factual error: In the scene with the host Kenny and Freddie at Capitol Radio. Kenny puts the record on a Technics 1200 Mk2. On November 21, 1975, "A Night at the Opera" was released. The single "Bohemian Rhapsody" on October 31, 1975, but the Technics 1200 Mk2 was released in summer 1978. (00:48:00 - 00:48:30)
Factual error: The drumkit Roger is using with Smile is a Sonor Hilite which was manufactured in the late 80s.