Mal tells her mother that the coronation is on Friday and Fairy Godmother says Family Day is on a Sunday. Yet during Family Day, Mal refers to the coronation as tomorrow, which would be Monday.
Throughout the movie Mal's hair changes between dark and light purple.
During the coronation Maleficent arrives and freezes everyone. She walks over to King Beast and removes his glasses and puts them back crooked on his forehead. The camera changes angles several times and the glasses keep moving from crooked to straight then completely disappear and reappear.
Mal puts the guard at the Museum of Cultural History to sleep and opens the locked doors with the aid of the evil spell book, but for the rest of the time at the museum it is nowhere to be seen.
At the end of 'Be Our Guest', we can clearly see Audrey's finishing pose is with her hands touching her head, but in the wider shot, it is shown that she ended with the same hand on her hip, then when the shot tightens again, we see her taking her hand off her head.
When the four children our trying to get inside of the museum you see the security guard sitting in his chair, but when it goes in for a close up of "Maleficent's spinning wheel" he is not in the chair. Then in the next scene he is back sitting in the chair.
When Mal, Jay, Carlos, and Evie arrive in Aurdon, as they are about to leave Jay's arms are crossed but in the next they are straight. Then change back to crossed.
After Ben eats the brownie Mal gives him in the carriage, you hear Ben say Mal's name but his mouth never moves.
Cruella says she needs Carlos to scrape the bunions off her feet. A bunion is a bump caused by the big toe joint being out of place. She likely means calluses.