What should the referee do if Fencer X’s attack misses and Fencer Y touches on the valid target as Fencer Y falls over backwards?

In the scenario where Fencer X’s attack misses, and Fencer Y touches the valid target while falling backwards, the correct action for the referee is to award the touch to Fencer Y. The critical factor here is that Fencer Y successfully landed a valid touch before the fall occurred. The rules indicate that a valid hit must take precedence in determining the outcome of an action, regardless of whether the fencer is in control of their body after the hit.

Awarding the touch acknowledges the successful technique executed by Fencer Y, emphasizing the importance of correct targeting over the physical condition of the fencer post-execution. The referee's role is to uphold the rules guiding valid touches, and since Fencer Y's hit was valid, it stands.

In contrast, annulling the touch and giving a yellow card to Fencer Y would imply that the hit was invalid or against the rules in some manner, which is not the case here. Issuing a warning to both fencers or restarting the bout would not appropriately give credit to the successful action of Fencer Y, thus failing to reflect the actual event that took place. Fencers must receive acknowledgment for valid actions, and in this instance, Fencer Y's touch qualifies.