Continuity mistake: When Tom is about to drop the iron on Jerry, he is holding some cheese on a piece of string in his left hand. When the iron drops on Tom's foot, he is no longer holding the string.
Continuity mistake: When Jerry dives into the bottle of invisible ink, he dives in head first. When he emerges from the bottle, it is the bottom half of his body that is invisible first.
Continuity mistake: When Jerry hides from the Tom in the bottle of invisible ink, the two test tubes on the right hand side contain red and yellow liquid, respectively. When Jerry emerges from the bottle, the liquids are now purple and blue.