Other mistake: When Chumley wonders how Jaden and Syrus are being so calm, Jaden replies with "What's not to be calm about?" and the shot zooms out to show several other playing cards on the floor. One of the cards shown is Cyber Twin Dragon. Jaden nor Syrus don't even have that card in their deck. Zane has it, but not Jaden or Syrus.
Other mistake: After Jaden has summoned Elemental Hero Rampart Blaster, Syrus states to Jaden that Gate Guardian's attack points are 3750 and Elemental Hero Rampart Blaster's defense points are only 2500. When Syrus is stating this to Jaden, it cuts to a reverse angle of Jaden and Syrus where Syrus says "Blaster will get blasted", you can see on Jaden's duel disk, the Elemental Hero Clayman card shown, rather than Elemental Hero Rampart Blaster.
Other mistake: When Jaden explains Elemental Hero Rampart Blaster's ability to Syrus and the Paradox Brothers, Jaden has Rampart Blaster attack the brothers directly. Just as Jaden says "Blast them with rampart mirage!", Elemental Hero Rampart Blaster is in defense mode somehow standing on top of the Elemental Hero Clayman card, rather than the Elemental Hero Rampart Blaster card.
Other mistake: All monsters in the series with effects are shown to be shaded in a dark orange color and all of the monsters with no effects whatsoever are shown to be shaded in a bright yellow color. Yet Dox's Defense Wall card is shown to be shaded in a bright yellow color (which implies that it is a monster with no effect), despite the fact that Defense Wall has the ability to be the only monster an opponent can attack whilst in defense position.