Elise killing Tyrndamere mid ult

So I was playing a match on the new game mode Black Market Brawlers as Tyrndamere and I was starting on top side. Well Elise dived me middle lane as I was heading toward my bot jungle and she almost killed me but I ulted and like 2 seconds later I died during my ult. I did not check what did the killing blow as I was kinda mad I died when I shouldn't have died. I would like it if you could check out any bugs on Elise that would kill a Tyrndamere mid ult.