Revealing mistake: There is a large painted hanging cloth backdrop of clouds in the mountain scenes near the end of the film. Vertical streaks can be seen in the backdrop that are the pleats in the fabric. These streaks really stand out in the restored versions of the film.
Continuity mistake: At the end of the movie when the blind flower girl (Virginia Cherrill),sees her tramp benefactor for the first time Chaplin's hand jumps back and forth away from his mouth in sucessive shots.
Revealing mistake: When the camera is tracking in to Peter Lorre whistling in the cafe, part of the screen gets noticeably darker because the camera is blocking one of the lights. This happens in other scenes, noticeably, when the camera makes shadows.
Other mistake: In the scene where Renfield enters Dracula's castle, it is past midnight and on the outside, it is dark. But there is a LOT of bright light streaming through the windows into the castle, throwing well-defined shadows. (00:09:10)
Continuity mistake: When Stan pulls the door into Oliver's face, Oliver falls backwards and the spring on his back sends him skywards and onto the piano. When Oliver falls onto the piano, you can see that there is nothing on his stomach, but a few seconds later he is covered with piano hammers and other parts from the interior of a real piano.
Continuity mistake: The second-story room of the prison warden's daughter is on fire and she is screaming for help. Stan has trouble connecting a fire hose to a water valve and Ollie winds up completely drenched, but in all the following scenes where Ollie is using a ladder to try to rescue the woman, his clothes are dry.
Continuity mistake: Near the end, when Tom Powers is waiting in the rain to murder Schemer Burns, we see Tom wearing a tall, straight-crowned fedora that is only slightly tilted to his right. Suddenly, and for no apparent reason, we see a close-up of Tom wearing a completely different, taper-crowned fedora that is tilted deeply to his left. This close-up lasts for 7 seconds, then the shot returns to Tom wearing his original tall, straight fedora.
Other mistake: A crewman tells the ship's captain he knows there are four stowaways because he heard them singing "Sweet Adeline," a popular barbershop quartet song. Harpo never spoke in any of the Marx Brothers films. The crewman could not have heard four voices.
Continuity mistake: When Stan and Oliver are speaking to the ice-cream salesman, the amount on the till reads "05", but after Oliver has given him the money to pay for the ice-cream, the amount is now "10."
Continuity mistake: When Bosko is sitting in the trench, he spots a piece of cheese on a mousetrap and eats it. In the next shot, the mousetrap has disappeared.