I only use Rescue on sprouts and returners, and only if not using it would result in their death. If the aoe won't kill them I'm letting them get hit.
This is more for my sanity than that of other players. So many players take its use as a personal insult even if it's abundantly clear the alternative was death. I don't want to deal with a diva who would rather die. Sprouts and returners rarely comment on it at all, and it's probably because some of them don't realise what happened lol.