So it would seem to me this fellow should be magic damage, correct?

So why am I taking such a high amount of damage from him? I'm my standard absorb spec, 51rs/7brd/8Rng, well geared at around 15.5k raid buffed.

How the hell am I taking 4500 a hit from his earth spike spam? 2700 absorbed only. Our guild War tank takes 2200 average from it. It was to the point I couldn't even tank it, we had to switch in a War for it. This is way out of scale with other magic damage fights like Alsbeth and Greenscale. I absorb nearly half of most magic attacks. Which leads me to believe it isn't magic damage at all, but that really doesn't make any sense.

So what's the deal with this guy? Anyone have issues with him? I'm taking our B group through here, they can't keep up with this amount of healing required.