Wow - either shamans do extremely poor DPS or DKs do way too much

Ok, so I finished a full run of Utgarde Keep earlier today.

My DK is fresh level 70. I bought him a full set of cobalt plate gear which is mostly stam and +defense, with a bit of +str. No crit, no attack power, nothing.

My shamans on the other hand are all level 71 (which gives a higher rank of flametongue weapon for more damage) - around 700 spell damage each.

My DK uses 2 buttons - death and decay on multi elite pulls, and then spams a tank castsequence. Despite this, my DK came out ahead of all 4 shamans at the end of the instance, even with using things like bloodlust, elemental mastery on all boss fights, trinketing, etc, and not using any special abilities on my DK (didn't even use my pet, gargoyle, unholy blight, etc).

I wasn't sure if I was excited for my DK or sad for my shamans after that. About 3/4 of the way through the run my DK was 7% ahead of the shamans - by the time I downed Ingvar I was only .4% ahead as the shamans did most of the dps on Ingvar while my DK mostly just kept him distracted and ran around in circles like a madman.

My pally has been topping the dps meters against my two afflic locks and one super-critty destro lock at least as long I've had Recount installed, but I presume since she first trained Consecrate. I think AOE tanks just manage to stay ahead of their backup by virtue of doing a small amount of damage to everything, every second of every fight.