Is Darius ulti supposed to do this?

I was in a normal game and the {{champion:122}} ulted me i {{summoner:4}} but i still died next time i tried to {{summoner:4}} but it didn't work. You can't dodge {{champion:122}} ulti when it's on you and the animation already started i dunno if it's a bug or just me but i can't escape a {{champion:122}} ulti when the animation went off. ( sorry about the pictures they're so fun to use)