Yugi vs. the Rare Hunter: Part 1 - S2-E7
Revealing mistake: At the start of the duel, Yugi draws a card from his deck and says, "I draw a card from my deck, now get ready." When he says this, the cards he is holding in his hand appear to be misshapen, as the tops of the cards appear to have curvatures at the corners when they should be rectangle-shaped. (00:15:04)