You are aware that parses for Sha of Fear aren't accurate because of the distance between Cackled raid members? The healer in that parse is the one who uploaded it. So yes, her healing is going to appear far greater than everyone else's, as on 10 man you are never in the same area with your fellow healer for more than 10-20 seconds at a time until (I believe) the third phase.
Ah, ok. Didn't realize that messed up the logs. Was wondering wtf their shaman was doing.
To be fair, there are also a lot of paladins solo healing the same fights, and some fights that for whatever reason I don't see any disc priest soloing (Elegon 10N - but I do see 10H). OP set bonus is OP.
And there are a few solo MW logs from before their nerfs. Don't see any solo shamans, druids or holy priests though.