The Forbidden Ritual: Part 1 - S3-E40
Other mistake: When Aster summons Destiny Hero Dunker, in the shot of him showing the card to Adrian, its attack points are 1100, as shown on the card. The monster then appears on the field, and its attack points are 1200, as shown by the attack point display. (00:14:52)
Conquering the Past: Part 3 - S3-E44
Other mistake: By removing Cyber Valley and Cybernetic Hidden Technology from the game, Zane can draw two cards. The two cards are two individual Overload Fusion cards. He activates one Overload Fusion card, and at the end of his turn, he places the other card face-down. When Jesse attempts to attack, he reveals the face-down, which is revealed to be Dimension Explosion. (00:08:52 - 00:11:54)
Return of the Supreme King: Part 3 - S3-E51
Other mistake: When Jaden summons Elemental Hero Clayman in defence mode, the shot pulls out slightly and Jaden says "And now I activate Rainbow Neos' second ability." At this moment, Clayman can be seen on Jaden's duel disk, and the card is placed vertically on the disk, indicating that it is in attack mode. (00:06:55)
