Continuity mistake: When the gang arrived for their first day of closed rehearsals the clock on the front of the theater says about 8:30, but just a few minutes later when Buster goes to get the power back on the clock now says about 11:50.
Sing (2016)
1 continuity mistake
Directed by: Garth Jennings, Christophe Lourdelet
Starring: Scarlett Johansson, Matthew McConaughey, Reese Witherspoon, Seth MacFarlane
Deliberate mistake: The morning after the flyers are spread, Buster is sleeping in a drawer. When his alarm clock goes off, he hits his head at the top of the drawer, but later on, he can be seen standing up in it, easily visible when he is putting his coat on. The drawer obviously became wider for him to stand up in it.
Buster Moon: Why aren't you rehearsing?
Frog: I'm through! They said I'm an intolerable egomaniac. I don't even know what that means.
More trivia for Sing
Question: What happened to Mike the Mouse? At the end of the film we see him escaping with his girlfriend, but the bear is latching on the car. This is the last time we see them and we don't see them at the reopening of the theatre, so what happened?
Answer: Mike had to stay with the bears for the rest of his life.
Answer: I think he escaped from the bear with his girlfriend, sped off very fast and the bears fell off the car.
You haven't read the question. Before it cuts to Meena's performance, the lead bear popped up from behind the car and presumably kidnapped them.