[GAMEPLAY] Fiora's w doesn't block a few abilities.

Fiora's w only blocks Malphite ult some of the time. I used Riposte twice this game to stop the ultimate. It worked once, and that happened the other time. You can clearly see the w's indicator go off before I'm knocked up and the ability goes on cooldown, yet the CC is not blocked...I also had this happen against a fiddlesticks' terrify but I don't have a highlight of that one.