irelias w bugged

Hey guys. im inquiring on the way irelias w works.. i looked up the wiki.. and read about it. it states that its a stun when she has lower health then her opponent. ok cool thats sounds reasonable. and if she has higher health its a slow. correct? so as my last game as yasou .. at level 1 she takes the w. and immediately it stuns me.. at equal health .. ok fine im just seeing things.. but again and again and again .. it always stunned.. me. im talking i even had lower health and it still stunned me .. everytime.. i even checked took minion aggro then baited the w out and what do you know stun .. im not salty one bit. i can admit getting out played or whatever.. but i dont like when a champ is abusing a bug. theres no way her w is supposed to stun every single time..i just want some feedback on this to determine weather this is a known bug or something that has just occured.

thanks for your time.. and hopefully i get some feedback on this..