Deliberate mistake: When Hannah is lying on the floor there's a mild breeze blowing, causing the flowers and her hair to move. Seconds before the movie ends, Hannah hears Chaplin's words and looks around. Although the flowers in the back keep moving, her hair is still for several seconds until the camera comes closer to her. Then the music starts in crescendo and her hair comes to life again, which makes a more dramatic ending.
Continuity mistake: When in the plane, after the German officer cries "Well loosen it", Chaplin is about to fall off the plane and the angle changes. The officer's white scarf then disappears, or at least stops moving, which is very strange since they're flying.
Continuity mistake: Chaplin spits 3 coins from the pudding. One falls and moves to the middle of the table. Another gets beneath a dish. And a third one falls off the table. A couple seconds later all three appear lined up on the table, close to Chaplin, ready for him to pick them up.
Revealing mistake: When the defective shell is about to fall, the ground has no sand mounts. Couple shots later, now on the floor, the shell turns around following Chaplin. Watch and you'll see that a sand mount has magically appeared close to the shell to hide the white mechanism that makes the bullet turn.
Continuity mistake: In the beginning, when Chaplin rescues the German officer and carries him on his shoulder, the officer's bag is first behind Chaplin's head, close to his back. When the angle changes it is now on the front, close to his cheek.
Continuity mistake: In the beginning, the defective shell fired by the cannon has several scratches on its back. Shot changes to the soldiers watching the shell fall, and when the camera cuts back to the shell on the floor the scratches have disappeared.
Continuity mistake: During the first speech, when we see a back shot of Hynkel the mics on Hynkel's right hand side are closer than they are in the front shots.
Continuity mistake: When Chaplin is about to deliver his final speech, there's a bunch of people on the right side, just where the staircase is. When Chaplin is ascending the steps the people disappear.
Continuity mistake: The barber and Hannah's walk gets interrupted by Hynkel's speech. The barber runs to hide and his hat falls on the street face up. Angle changes to Hannah and when back to the barber the hat is now facing down.
Continuity mistake: During dinner with Napoloni Hynkel asks fro strawberries. The spoon inside the English mustard moves to the right between one shot and the other.
Continuity mistake: At the end of the pudding scene, when Hannah shows up, the sugar bowl left of Chaplin moves from close to a glass to the far right of the table.
Continuity mistake: When the train station sequence begins the Bacterian ambassador extends his arm to salute twice.
Continuity mistake: In the first part of the movie, the two men in the airplane keep switching sides of the cockpit.
Continuity mistake: When Mrs. Napoloni gets trapped by the guards, the suit of the handsome man behind her, with a hat and a coat hanging on his left arm, swaps from light coloured to black.
Continuity mistake: When Hannah and her family enter Osterlich, her right hand swaps from being close to the white blanket to slightly away from it between shots.
Continuity mistake: Chaplin stands up to deliver the final speech, takes off his cap and we see his hair is short and flat. When the angle changes to a close-up the hair is longer and fluffy.
Continuity mistake: When the plane crashes, Chaplin is sunk in a pool of mud. When the officer talks to him he is covered except for some of his hair, two seconds later he is totally covered and the mud is more liquid.
Continuity mistake: During the final speech, after Chaplin says "Millions through out the world." The shot changes to Hannah. When back to Chaplin his tie has moved to the right, two stains have appeared on his shirt (close to left armpit and close to right collar), and his hair is combed. Two shots later the shirt is clean and the tie straight.
