Character mistake: When Rogue asks Storm what her plan is for dealing with the closing walls, Storm says "You three stop the walls, I shall slow the ceiling." Besides Storm and Rogue, Jubilee, Jean Grey, and Gambit are also there, so Storm should have said "You four stop the walls." (00:03:12)
The Tale of the Manaha - S5-E7
Character mistake: Near the beginning as the leader is about to set off with the boys, he says, "About face!" and turns to the left, and the boys follow suit. But "About face" means to turn 180°. He should have said "Left face" to get them to turn 90° to the left. (00:04:25)