Darius W, Crippling Strike, bug

When playing as Darius, if you use your w, Crippling Strike, and wait for the timer to almost time out entirely before you use it to attack, the animation for Crippling Strike will play, but you will not deal damage to your target. This bug has never lost me a game or a kill, but it has certainly lost me cannon creeps.

This wouldn't bug (pun intended) me too much except for the fact that Darius doesn't even deal his basic attack damage to the target, he just plays the animation and the target loses 0 health. This effectively means you're not dealing damage for a good half second.