I think the reason people are seeing this as a bug is because we as players would look for a fail mechanic to reset the raid instead of continue on in a no win situation where Grolik is locked and no way to unlock. After reviewing our logs of many failed runs, it seemed that Grolik would lock fairly consistently after the sixth round of orb to aura completion. Grasping at straws here, but could it be some remnants of the locking/unlocking that was originally on the beta version but got removed for live? Was it a counter that after six misses of no echo of shadow hits on Grolik, he would lock and then you would need to unlock him? I would be curious, the guilds that did win, did you have casters with the echo of shadow every round and dropping bombs on Grolik, so you would potentially not get him to lock/bug?