When Crickett Kelly jumps out of the window, one of her shoes falls off, but in the next shot of her landing on the net, that shoe is back on.
Moe very obviously blows a line and momentarily drops character when he says to Curly: "What do you expect a fire mouse...uh...I mean, a fire house mouse to smell like, a petunia?"
Curly also blows a line - "The horse falls on the harness - I mean the harness falls on the horses...".
When Moe pulls the string, his hat falls off and he can be seen trying to get it.
When the horses are first being hooked up you can see Moe's hat backwards but in the next scene his hat is forwarded.
When the Stooges are about ready to rescue Chief Kelly's daughter, you can already hear her screaming, even though she is supposed to be unconscious.
When the duck's explosive egg explodes, the tiny charge inside blows up, but it takes another second or so before the bigger charge goes off. Another example of Chase's unwillingness to reshoot a scene.
When the Stooges and their horses are in the Turkish bath, Moe calls one of them a he, then a she.