Continuity mistake: The blood Ashe smears on her face changes its pattern and consistency several times as the shots change. (00:36:00)
Duel Identity, Part II - S1-E30
Character mistake: Yugi mistakenly says if he doesn't get a monster out to defend himself Mai can attack him directly, which wouldn't be possible since the rules of Duel Monsters during the Duelist Kingdom arc forbade direct attacks on defenseless opponents. That rule wouldn't be implemented until the Battle City arc.
The Origin of the Silver Surfer: Part 1 - S1-E1
Continuity mistake: When Norrin Radd is placing the Kree and Skrull weapons on the rock, he is lying them down on the edge of the rock furthest from him. When the shot changes, he places them down on the edge nearest to him.