Xin Zhao and Fiora bug

During a ranked game playing as Xin Zhao, i was using my Three Talon Strike on a Fiora, and when she used Riposte at the same time i was using my Three Talon Strike, my attack speed was reduced to zero, making it so i was unable to attack for about 3-4 seconds after the riposte had ended. After the match we entered a custom game to try and repeat the results and found that it was a bug that occurred every time these 2 abilities interacted.