When Buster Moon is trying to get the power back on to the Moon Theater, he has trouble connecting the power cord to an outlet, a reference to Back To The Future.
Another reference to the movie is when Ash slides on her knees during her guitar solo.
Mike calling Meena "Dumbo" references the Disney film and character of the same name.
Buster owns a helmet that resembles one from Gladiator.
Fire extinguishers do not work unless the pin is pulled, which Meena did not do when she used it to put out the fire.
Ash's boyfriend Lance plays left-handed with a left-handed guitar at the start. There's a scene a short while later where Lance is sitting on a sofa playing his guitar right-handed and the guitar has switched to a right-handed model. Further on in the film, Lance and his guitar are left-handed once more.
During the final presentation, some keys of Johnny's piano are replaced by pieces of wood. However, when he starts playing, all keys are white.
In the character montage at the beginning of the movie, Mike is given a penny by a baboon. Mike reaches out and grabs the lapels on the yellow shirt, but in the next shot he is pulling the green sweater.
In the final presentation, a gorilla sitting behind Meena's family changes shirts between shots: first, he's wearing a white shirt with blue sleeves; then, he's wearing a plain green shirt.
Sandwich filling falls on Eddie's shorts in a scene. When he leaves the restaurant, his shorts are no longer dirty or even stained.
When Buster goes to steal energy from a store that sided with the theater, the ledges of both places are aligned. When the shot opens, the ledge of the store is much lower than the Moon Theater's.
Ash's guitar has fret inlays on the 4th, 6th, 8th and 13th frets. Normal positions for inlays are on the 3rd, 5th, 7th and 12th frets. The inlays don't affect the playability of the guitar, but they serve as visual guides for key positions on the fret board and can confuse a player who relies on them.
During the entrance scene, when Buster Moon narrates "his plans to become the first koala bear in space were suddenly... toast." Depicts a common mistake that a koala is a bear. In all actuality it is a marsupial. However, this may be intentionally written in the story line because of the widely known use of this misnomer.
When Meena and Buster are stealing water from a large tank, the hose they use to send it back to the Moon Theater is bent to the right side of the tank. In the following shot, it is flat and straight ahead from the tank.
When the theater crashes down, some debris fell in front of the theater, yet when the camera opens, it's not there.
During Mike's performance, the police helicopters send him flying upwards. This would never happen - helicopters cause a downdraft.
When the theater collapses, the ornaments on top of it seem to crash down in a different motion than the rest of the theater. It should've fallen to the inside of the building, not to the outside.