When Snow White escapes to the cottage of the Seven Dwarfs, she is scared by the animals in the forest. One of them is a puma, an animal from America.
As two of the men are carrying the unconscious body of Prince Charming out of the castle, the Prince's hand is shown holding onto the shoulder of one of the men to keep from slipping.
When the transformed-into-a-witch Queen flies out of the window, the wire used to lift her off the ground and out through the window is visible.
When the Stooges play music to Snow White, Curly Joe plays a concertina, an instrument that was not invented until 1844.
Count Olga tells the stooges to begin performing at 8 o'clock. Measuring time by the hour will not be known for another 500 years.
Count Oga's laboratory has test tubes, flasks, beakers, steel rods, and plastic tubing; all of which won't be invented for another 600 years.