The Champions League match between Atlético de Madrid and Real Madrid on round of 16 is still the main topic of conversation today, and specifically, the penalty shot by Julián Álvarez that was ruled out by the rule of the "double touch": Álvarez seems to hit the ball with both feet when he strikes, something that is forbidden by the Law 14.1 of the Laws of the Game made by IFAB.
The controversy has been huge because not a single TV replay seems to confirm nor deny that the Atleti player hit the ball with both feet, which was almost decisive for Real Madrid victory during the penalty shootout, which ended 4-2 in favour of Real (another Atleti player, Marcos Llorente, also missed his shot). As the noise is increasing around the topic, UEFA has released a short statement standing by the decisions of VAR officials and the referee Szymon Marciniak.
"Although minimal, the player made contact with the ball using his standing foot before kicking it, as shown in the attached video clip. Under the current rule (Laws of the Game, Law 14.1), the VAR had to call the referee signalling that the goal should be disallowed."
UEFA has also released a video from a new angle, not seen before on TV, which seems to confirm that yes, indeed, Julián Álvarez hit the ball slightly with the left foot before striking with the right (almost at the same time), although it only happens because the player slips (there were quite a few slips during the whole match, actually).
In other words, Álvarez breaks the rule completely by accident, and with such a small contact that it may not have even affected the ball trajectory at all (although that is impossible to know for sure).
Atleti players will likely find little comfort knowing that "UEFA will enter discussions with FIFA and IFAB to determine whether the rule should be reviewed in cases where a double touch is clearly unintentional". However, the elimination of Atlético de Madrid from Champions League is irreversible, despite fan groups from Atlético de Madrid asking for the match to be impugned.