Ashran: unkillable players: hax or intended?

So I went to Ashran on my horde premade and met an alliance player. It was guardian druid. My hp about 200k, his hp over 3mil. He one shot me in bear form when we met for the first time, one shot me with moonfire the second time. Moonfire of guardian druid was doing about 20k damage each tick.

Is it intended or some kind of hack?

Screenshot of his HP: http://i.imgur.com/WJoQjep.jpg