Other mistake: Star keeper Genzo Wakabayashi has a trademark hat with his name and a cool logo. According to his manga character design he was supposed to wear the Adidas logo, but copyright issues arose and the Nankatsu logo is a great substitute visually - sadly it makes no sense, because he is sporting it already at the beginning of the anime and the team with that logo will be properly formed only later in the series.
No Easy Way - S1-E12
Audio problem: At the beginning of their conversation outside the house, the Captain and Roberto's audio is off-synch with the mouth animation. (00:01:40)
Kick-Off for the Future - S1-E3
Trivia: International versions change Roberto's message to his coach at San Paulo FC, adding for some reason that he met a girl he fell in love with. This girl is never referenced nor appears, since, well, she does not exist? Roberto mentions that he met Tsubasa instead, who he wants to bring to greatness. (00:12:40)