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)
Factual error: When water starts flooding Brooklyn, the water floods the main road but never floods the side roads. (00:12:21)
Factual error: When King Koopa looks in the mirror, the reflection is not reversed. Additionally, it would not be possible for him to get a reflection of Mario and his friends since they are underneath him. (00:12:24)