Visible crew/equipment: When Dorothy first enters the room full of ornaments, the camera pans backwards, away from her. The camera passes tables of ornaments. Watch the large blue vase to the right of the screen, and a cameraman can be seen reflected in it, walking backwards with the camera.
Visible crew/equipment: When Dorothy, Tik Tok and Jack are eating and drinking in the Nome King's lair, Tik Tok says "What is it we are risking?", and there is a small explosion, causing the table to fall, and them to all fall back. A wire attached to the table to make it fall is visible to the right of the screen.
Continuity mistake: When Dorothy finds the small green glass ornament, she shouts "Oz!", and the Scarecrow appears. In the shot when Dorothy calls "Oz", there are two large ornaments to the right side of the counter. Then when it cuts and the scarecrow "appears", the ornaments have now moved a few feet away, so that the Scarecrow can comfortably "appear."
Revealing mistake: When Mombi's headless body awakens and sits up, in the first two shots it is easy to notice that her body is actually simply a puppet of some sort, as the motion is not very fluid and it looks like a mannequin. Once she stands up, she becomes an actress whose head has been removed with special effects.
Revealing mistake: When Dorothy steals the key from Mombi's cabinet, as Mombi's body picks up her head to put on, you can see a small error. As Mombi lifts up her head, you can see the bottom of the cabinet warp slightly for about two frames (slow motion helps but is not needed), revealing that the actress simply had her head through a hole in the bottom of the cabinet (to make it appear severed), and her shoulders bumped into the bottom, making it shake/warp for a second.
Continuity mistake: When Dorothy and Billina are in the crate surrounded by water, then water begins to soak up, so that it gets very shallow. In the next shot over Dorothy's shoulder the water is suddenly more deep and rippling again. Also, the sand, once it dries up, goes from damp to drier.