Factual error: In this episode we have a random person showing up and being admitted to the team and playing as substitute on the spot, with nobody protesting. He puts on the (sweat-soaked, presumably!) uniform of another player and just goes ahead without any check from the referee or assistants. Given that the match is between two schools without necessarily having the official football federation involved, it is understandable, but they do not even ask the opposing coach if they are OK with something so obviously outside of any established rule. And they are still playing in a packed stadium, with official referees and even a radio commentator! Only in anime.
The Football Is My Best Friend - S1-E4
Audio problem: When Tsubasa says bye to his friends from the top of the overpass, his mouth is not animated for the greater part of the line. (00:04:30)
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)