Revealing mistake: When the Wicked Witch scares the Munchkins in Munchkinland, where Dorothy lands, she disappears into a cloud of smoke she creates. But you can see her sneak down into a trap door below. [As a sidenote to this entry, Margaret Hamilton was hospitalized for severe burns after a take of this shot (not the final one used) when the stage elevator got stuck and the explosion went off.] (00:30:45)
Revealing mistake: When they are feeding Annie the Elephant medicine with a wooden spoon, there is obviously no fluid in the spoon.