Evelynn Stealth Bug

Recently encountered in a ranked game, Evelynn was able to remain stealthed even when in extremely close proximity to enemy champs. According to the opponents the ! would appear above her head but it did not for any of the allies (vs evelynn) game breaking she was able to stand next to our jungler and smite steal and run away. Only thing that made her visable was towers pink wards and breaking stealth