If you can bring another Shaman the fight will be very easy
A glyphed grounding totem absorbs all the damage during Getaway. Since you only have one I suggest you put the ScaryFog people into the group with shaman, and anyone who doesn't have good self-heals. To answer the OP though, I think a DK is good enough for both specials. During Getaway he can just pop Pillar of Frost (glyphed I presume) and nuke the boss freely because it makes him stand still.