Last night on 25 man Zor'lok we noticed that when I got hit by Convert (shadowpriest) and he used my Devouring Plague during the MC, the healing component actually healed him for at least 4%. We ended up wiping at 3% that try....
Looking at WoL logs it seems that all abilities used by MCed players during Convert are considered as if used by Zor'lok himself. And since the healing part of Devouring Plagues is a % of maximum health, he heals for massive amounts if this happens.
My question is if you would consider this a bug, or unfortunate RNG? Any other spells that could screw with this boss in similar ways? We got him down later, but it still annoyed me quite a bit.