Revealing mistake: In many scenes, particularly the dance scene in the bar, Michael's wings disappear and/or reappear. If you look closely throughout the movie, his wings are often completely gone.
Revealing mistake: As the Wormwoods are driving out of the hospital parking lot at the beginning of the movie, the shot of the car driving from right to left has been flipped, as evident by the quick appearance of a hospital directory sign in the background being mirrored. (00:01:48)
Revealing mistake: After the Martian who is dressed up as a women spits a finger in the fish tank a bit of the Martian's mask near its mouth is torn away. As she chews the nitrogen gum the human lips move but her real teeth don't. (01:04:20)
Revealing mistake: After Draco flees the cave, Bowen is riding his horse in the water after him. You can easily see that it isn't Dennis Quaid but his stunt double.
Revealing mistake: After Lucy discovers Mrs. Bradley in her bed, as she fights off and runs from Patricia, it is obvious that she wears knee pads for these shots.
Revealing mistake: When Le Merchant is offended by his wife's comments and puts the Lament Box into the travel chest, a section of the gold veneer on it has bent upwards.
Revealing mistake: At the end, when the NYC children are rushing toward the peach to scoop out a piece to eat, you can see one little girl running with a piece of peach already in her hand.
Revealing mistake: When Joe is beat up the second time when he just gets off of the bus in NYC, during the simulated punches his head hits a sheet of Plexiglas. The makeup from his forehead leaves a tan stain on the Plexiglas.
Revealing mistake: When Doug 2 wakes up and sees Doug 1, Michael Keaton's body double is noticeable in the angle shot from behind - he has bulkier hair.
Revealing mistake: When Buddy throws Reggie at the piano, you can see it's his stunt double instead of Buddy.
Revealing mistake: When the Leprechaun gets sucked into space, he grabs onto the edges of the cargo bay's doors. You can see pieces of his hands disappear into the doors, showing that it's CG.