Quote Originally Posted by Arkenne View Post
I don't have a WHM, or a healer at that, but if «Stoneskin II» has the condition of "only if not in battle" then just as «Hide» from the Rogues you'll be able to cast it at any point in the fight so long you aren't fighting a boss and your enemy list is clear (haven't throw any heal, attacked any enemy or got targetted by any enemy yourself).

If it worked on a boss fight thats just the spell clipping in which spells cast so long 90% of the casting bar has been completed. Not much utility I can see there, besides from recasting stoneskin on the Tank for an aditional shield refresh. Then again, I am no healer, so I can't tell.
This is indeed the behaviour of Stoneskin II. As long as the whm's enemity list is clear, the whm can cast it. However, the spell will only land on party members with clear enemity list.