No, it's expert roulette, you should expect to occasionally run into people That're still learning the level 60 rotation of an off main they haven't used much, as well as re-acclimating to their job skills. Further to the point, healers do actually get to ignore skills that they don't need, such as their entire healing repertoire sans maybe lustrate for Scholar. Further, most healers I've seen will ignore the HP of the DPS after raid wide damage if they feel the can finish the fight faster with DPSing themselves, letting them ignore medica/Helios, etc.