The Whirly Dirly Conspiracy - S3-E5
Continuity mistake: When Beth glues the horse hoof on, the bottom is facing up. In the next shot it facing to the side. And then the leg changes shape in different shots.
Continuity mistake: When Connie starts reading The Unfamiliar Familiar to Steven, she starts at the very beginning of the book. A couple cuts later, as she continues to read the same passage, the book is now open to the middle.
Continuity mistake: Sometimes Cyborg is waterproof and sometimes he isn't.