Deliberate mistake: Ash's car breaks out into the courtyard and the whirling, windmill thing batters the Deadites aside. We see the carnage a couple of times filmed from different angles, one Deadite, planted, legs apart, gets battered twice and the guys who come in from the left and are quickly jerked off screen are shown again seconds later.
Deliberate mistake: As Joey is running down the street and having things blow up all around her, you can see other people walking on the sidewalk not reacting to the destruction around them, even when something blows up just a few feet from them.
Deliberate mistake: When Jafar sees Aladdin reflected in Jasmine's crown, Aladdin is the only thing visible. This isn't possible- we should have also seen the background of the room, the objects around him, etc.
Deliberate mistake: Gonzo and Rizzo are selling apples in the beginning, including the Red Delicious cultivar. That wasn't invented until the 1880s and the story is set sometime in the first half of the 1800s. Most likely intentional as they are the narrators.