The Leap Home (1) - November 25, 1969 - S3-E1
Factual error: The Post Raisin Bran cereal box sitting on the Beckett family breakfast table in 1969 has a 1990s box design. (00:18:00)
Factual error: Zelda gives Prince Facade a compliment when he meets her father. Facade smiles and then looks over, the camera follows his view to a mirror on the wall. It then cuts to the mirror showing his reflection as he winks at himself. The problem is though, when the camera was panning from his position, it showed the mirror was against the wall a good distance from him, as well as facing almost a 90 degree angle away from him. So not only was his reflection too big for his distance, but the mirror would not have reflected his image back to him at that angle. (00:36:40)
Robo Koopa - S1-E52
Factual error: Koopa tries to kill the Mario brothers, Bunsun and Dr. Nerdnik by pushing an electric pole at them. Mario and Luigi use a nearby fire hydrant to protect them by having water rush out of it and keeping the pole from crushing them. There is no way a single blast of water can stop a large pole from falling, and the brothers would have been electrocuted as soon as the water hit the pole. (00:07:00)