When Curly crashes through the basement ceiling, he is soaking wet, but when Moe orders him to get another piece of pipe, he is completely dry.
The dirt on Curly's forehead when he is pulling the wires out of the pipe disappears when he drags it over to Moe.
Moe loosens his tie when he and Larry are trying to repair the broken pipe, but in the next shot, the tie is neatly around his shirt collar.
The crowd at the magic show differs in various shots, with different pedestrians standing in different positions.
When Curly is building pipes in the bathroom to stop the flow of water while standing in the bathtub, you can see the entire tub filled with water, in one shot. it is not possible for someone to take a shower with the drain plug in.
When the Stooges first enter the basement and run around in circles, Moe can be seen slipping and falling down and immediately getting back up again.
Parts of the pipe maze can be seen next to the hole in the bathroom floor when Curly returns there and puts the rug over the hole he fell through earlier.
A wrench magically appears in Moe's hand when Curly falls through the basement ceiling.
When Moe touches his hand on a steaming hot pipe, his pained yells are obviously dubbed in.
The laughter of the audience at the magic show is not in-sync when the Stooges are noticed by the policeman.