[GAMEPLAY] Attacking as Diana's passive runs out bugs her attacks

Was playing Diana and i attacking a minion with two stacks of passive just as the passive was running out. I showed the animation for the third auto, but i think it didn't deal the extra magic damage. But, on the buff bar, it said i had three stacks of her passive, and after getting to the third one again, Diana still had the outline that indicates she has the third auto, even after i had already used it. https://drive.google.com/file/d/0B2btCm9OpD59QmRWY3lDT1ZtMFE/view?usp=sharing