Continuity mistake: When it shows the chickens on the farm, just before Toto runs over and scares them all, the position of the brood of chickens is completely different between shots, and the branches and logs around them have also changed around.
Visible crew/equipment: In shots of Dorothy and Ozma running away from the doctor's clinic, there is a noticeable outline of kneepads under their dresses, and as Ozma slips down the muddy bank, and into the river, her dress momentarily rides up, revealing it quickly.
Continuity mistake: When the group lands on The Nome King's mountain, we see Tik Tok land with his body buried in the snow. Then in the next shot he is suddenly less buried than he was in the first shot. Then in the next shot he isn't even buried, and is just laying on a rock.
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.
Answer: The fire made the authorities discover the abused patients they'd locked in the basement.
Brian Katcher