Irelia's Defiant Dance gets interupted by Ornn Brittle

I was in game, and it occurred a few times, but I thought it was just user error. But in the final battle, I very assuredly left my finger on the W key. I was being massively cc'd and the end result would have been the same, however I noticed that Ornn's activation of brittle through an auto attack, did in fact, end the channel of my defiant dance. I later tested it out on a custom game with a friend and confirmed, W will continue through the animation, but the channel is interrupted. Riot, please check into this small minor issue and tell me if it is a bug or not.