Champion or Chazz-Been? - S2-E2
Revealing mistake: After Bonaparte has introduced Reginald, it cuts to Jaden, Syrus, Alexis and Crowler sitting in the seating area. On the third row are two Slifer Red students. The first is looking at his cards, while the second is looking at the first student's cards as well. Later on, when Reginald has Gilford the Legend attack Chazz, it cuts to Jaden saying "Here we go", and those two students are in the exact same position, looking at the cards. Clearly the same animation was reused on both occasions. (00:03:58 - 00:11:03)