Yasuo vs Warwick bug [GAMEPLAY]

Hello, I haven't play for a while but today I decided to go in jg with Warwick, everything fine until Yasuo appears. We start the thread and he has the tornado ready, he drop it at same time I drop my ult agains him. He can use ultimate agains me meanwhile my ult was there. Check it out, I dont have any prof of that, but it happen.