I don't know if it was a "bad" whm. Maybe it was their first time there or they are still new to mechanics. Who knows really. I also here that ps3 players have a harder time healing. Some overuse the sleep spell to make up for it. Were you marking mobs during the dungeon? Were the dps attacking the sleeping mobs? Sometimes people don't explain anything. You could say "Sleep the mobs" and in their mind if they haven't done it before it literally means to them "Sleep all the mobs." Of course this is a mmorpg. You are playing with people of all kinds of ages. Just expect the worse to happen.

If you were having a problem with someone you should have taken a moment and explained something to them. They'll never learn if you don't do that instead of complaining about them here.