Revealing mistake: Stan is using a block and tackle to hoist Ollie up to the balcony of Finn's apartment. When Stan lets go of the rope, Ollie falls and lands flat on his back. It is obvious by the awkward angle of the legs that a dummy was used. In addition, the dummy lands with the legs close together but in the shot that follows, Ollie's legs are far apart and one leg is in the air.
Continuity mistake: When Stan and Ollie arrive at Brushwood Gulch, they show Mickey Finn the deed they've got for Mary Roberts, and it has a couple of holes in it from where Stan has been keeping it in his shoe; Ollie even unfurls it to show the camera it's got holes. But in every other shot after that, whenever the deed is shown, it's got no holes in it whatsoever and is perfectly clean.