Rammus gameplay bug

In my last game i taunt the Jax while he jumps on the ward. Result was that sign of taunt appears above his head, but he just run away from me even tough that sign was above his head. In same game i Q Lux while she cast her R, but that didnt interupt her casting. I do not have a replay of this game. Here is internet page of that match. http://matchhistory.eune.leagueoflegends.com/cs/#match-details/EUN1/1488995338/200726113

Thank you

InfinitimCZ