The community so far.......

[LionKing]

Just leave the dungeon, I rather face 15 min cooldown from DF then run a group of idiots for 30-40 minutes. As a tank you should decide the pace and not them.

Just done Sunken Temple and in my group there was a idiot black mage, who kept spamming sleep, instead of doing damage. We tried kicking him out, but it failed, because the healer was his friend. After explaining to him that doing sleep was a bad thing, he told me that he knows this and wants to only cast sleep, because he can. This is one of the reasons why we have a shortage of tanks, to many idiots ruining for the good dps players.

/rant

OP, just leave, do not bother with the headache.

1/ Did he just cast sleep only? Then he is an idiot.
2/ If he cast sleep and you break it or whoever break it due to AoE, then either tell him not to sleep or you mark the target that will be tanked, so the whole PT focus the marked target down instead of AoE.
3/If he cast one sleep, then follow with the BLM rotation, then I think because he run with his friend, as a healer, he cast sleep to make healing easier. At the level for Sunken Temple, those Mobs hit pretty hard, especially Bee. I, as Ilv 103 tank, when run this Duns, I still die with 2 Bees on me. Those Final Sting bite like a truck.