Continuity mistake: At the races, Wimpy has Swee'pea at the line up board, asking which horse to bet on. As Castor walks in, the shot cuts to Wimpy at the board. The number 7 slot is empty, and no attendant is there. As the shots alternate between Wimpy and Castor, there is an attendant behind Wimpy erasing slot 7, starting to write, then gone again after Castor goes by. In the next moment, Wimpy is directly in front of the board asking Swee'pea. After picking Holy Moley, the next wide shot has the attendant back again with a name in slot 7.
Continuity mistake: At the betting window, Wimpy is holding the money he won with the top serial numbers toward his left side. When Olive grabs the money from him, she did so in a way whereby the money would not have been turned. However, the money is now the opposite way from how Wimpy held it.
Continuity mistake: In the beginning, there's a citizen ringing the bell. If you look carefully, the church appears to lit by strong daylight, but it's supposed to be stormy. After the bell ringer is done, the light strengthens as if the ringing awakens the town. The lighting on the church doesn't change at all.
Revealing mistake: After Bluto knocks Popeye out and he falls into the water, Bluto goes to jump in after him. Watch the water. Popeye just landed, but the water is really calm. And when Bluto hits the water, it's right on top of a face-down floating Popeye. As Bluto hits, Popeye's body bends almost in half backwards, revealing that it's a foam rubber mannequin.
Visible crew/equipment: After Olive threatens Wimpy, she goes to enter the Commodore's boat. When the camera is looking up the stairs to see her foot entering the shot, you see shadows playing on the ceiling and stair well. If you watch closely, you can tell that the shadows are of the camera man and the camera.