Evelynn W bug

Im not sure if its a bug or not but when i W'd a katarina under tower as evelynn and then procc'd it with my q she was still able to flash away even though she was being affected by the charm. I have video evidence but it seems i cant post it on this discussion. My IGN is ShotYouTwice on NA server if you wanna check the replay. as i said im not sure if it was him out playing me or if its actually a bug but i think its worth looking into anyways.