Canceling Gangplank's Q still places it on cooldown

Since preseason, I've noticed that Gangplank's Q (Parrrrley) will go on cooldown if you Q a minion that dies before you are able to fully cast Q. To replicate, simply q a minion that will die immediately after. You will here the "click" sound of GP cocking his pistol before firing, and depending on the timing, you may also hear the "boom" sound. But even if you just hear the "click", the ability still goes on cooldown.

I had thought at first that this was just an unfortunate patch, but there were no references to such a change in the patch notes. Additionally, thematically it doesn't make sense. A pirate cocks his pistol but doesn't fire, and so he has to wait several seconds...to reload?

It isn't terribly significant, it actually is helpful to learn when to use your q's more effectively (IE, don't use them when the minion will die first) but that's neither here nor there, it's still what i believe is a bug, so I'm reporting it! :D