If you're a deathknight and unholy you should know by now that if you die, you turn into a ghoul for a minute while doing useless attacks before you die.
I figured out a way to get out of it but it requires you to be next to an instance. Basically, die and turn into a ghoul, then zone into an instance and you'll turn back to normal.
Figured this out while fighting off the AC at a meeting stone, zoned in and was back to normal. So I went outside and began fighting again, pretty sure I confused them for a bit :]