when snowman hits a mob the mob doesnt take damage

Hi i saw a bug in 1.8 pre 2 realse its not only on that it was in the other versions too. when a snowman hits a mob with he's snowboll it makes a arrow sound and the mob doesnt take damage it just show up the red thing on the mobs body when a enemy to the mobs hits them (the red thing on the body isint a bug) and the mobs just make sounds

//IsS127