Why was Julián Álvarez penalty against Real Madrid ruled out?

The knockout between Real Madrid and Atlético de Madrid ended in the most dramatic way possible, with a penalty shootout that ended 4-2 in Real Madrid's way. Antonio Rudiger scored the decisive goal: Lucas Vázquez missed his shot for Madrid, but Mbappé, Bellingham and Valverde scored. For Atleti, Sorloth and Correa nailed their goals, but Marcos Llorente missed... and so did Julián Álvarez, but for a very unusual reason.

Initially, Álvarez scored, but the penalty was quickly ruled out by VAR. They found that Álvarez had touched the ball twice before striking. The moment was barely noticeable, and replays are creating a huge controversy.

The rule is clear: "the kicker may not touch the ball a second time until it has been touched by another player of either team or goes out of play (including into the goal)." In other words, the penalty can only touch the ball once, and in the case of Álvarez, he touches slightly (very slightly) with his left touch before striking with his right foot. The moment is barely noticeable, but it is there, and to make things more dramatic, Álvarez only does it becuase it seems to slip before striking.

That is why Álvarez goal, the second one Atleti shot in the penalty shootout, was ruled out (not repeated, ruled out), thus helping Real Madrid eventually winning the match and passing to quarter-finals, where they will face Arsenal on April 8-9 and April 14-15.