Continuity mistake: During the interview, while sitting, his striped pants are unzipped for a few cuts, then they are zipped in later shots.
Continuity mistake: When Elton and John Reid are kissing in the cupboard John's hand keeps changing between shots. John's hand rolls down Elton's chest, then the next shot it's on Elton's cheek, the next shot he takes his hand away, then the next shot his hand is by Elton's mouth and Elton pretends to bite John's thumb.
Continuity mistake: After Mick Mars has Nikki and Tommy kick the guy out with the guitar at his audition, the guy leaves and cries through the door. Nikki is standing by the door and looking nearly straight forward as the guy leaves, but then the camera changes angles and suddenly he's looking more to the side towards the door. Also his arms are a little higher up holding his guitar.
Factual error: The film is set in 1987 but most of the street lights seen throughout the movie are LED street lights and some high pressure sodium Philips lanterns (produced from the early 1990s to early 2000s), neither of which were around back then. Similarly many of the shots of the M1 motorway show modern cars and smart motorway/variable speed limits, which never existed at the time.
Continuity mistake: The evil stepsisters shove Kat at the feet of Dominic with latte splattered all over her face. But the mess looks different in the various shots. For instance, in the close-up when he asks her if she's okay and if she hurt herself there's a big splotch by the corner of her mouth, which was not there earlier (she was dirty under the nose at most) and is gone in the next shot. (00:04:00)
Continuity mistake: After the cartoon segment, Deni entertains some playful banter with his girlfriend and takes off, putting a shirt on while he runs. When the neighbour asks him "Late again?", the guitar strap is on opposite sides of the instrument as the editing switches to a reverse shot. (00:06:40)