[GAMEPLAY] Renekton W does no damage when flashed or sometimes dashed away from

On Renekton, on VERY fringe cases [lee sin W, flashes, irelia Q] Renekton's W will not do damage if the dash is PERFECTLY timed against him. This affects me more than it should and is hard to reproduce but I've been able to get it somewhat consistently. Renekton will waste time doing his W animation and it will go on cooldown, however the enemy champion is unaffected.

1. Have opponent ready to dash
2. Walk up and W the opponent
3. Opponent dashes or flashes away [usually max range dash or flash] and is unaffected by Renekton W It it SUPER hard to get the dashing timing correct but it is a seriously annoying issue as a Renekton main. Apologies for the terrible quality but its what i could get done while trying to reproduce. Link again to the gif: http://gyazo.com/90eaa287f6fc7702e13ca414be9d24c5