So Ill tell you guys how I (we) do it. Ive successfully healed it with a juggernaut, assassin and pyrotech so it really had nothing to do with the tank type, it had more to do with the dps.
The strategy we use is for everyone to have their backs against the wall that is directly facing the boss. Everyone clusters in range of my aoe heal. At that point it just basically comes down to me healing everyone. Its not the most glamorous strategy, but the boss doesnt have any sort of cleave or aoe, so getting everyone in the healing pool makes life so much easier. It was (I tried it one time) significantly more difficult to heal when everyone was spread out. I have also not found a range where I could not be stunned, I just make sure that I use my CC breaks. I generally do it on the 3 and 4 stomp, because the 1st and 2nd my force and everything is still usually fine.
The only thing is that the dps must beat enrage timer. The enraged smashes are likely to wipe the party, so dps must beat that. Its actually the same for all bonus bosses. Your healer should be able to heal through until enrage, so its actually more of a dps check.
I agree with his strat. I am an operative healer, and it was a REAL pain with people spread out. Once we noticed stacking like he said with our backs to the wall. The boss was just a cake walk and we down him now with ease everytime. Just a touch more work for me, but its pretty simple to heal with everyone stacked on one another. Give that a try and I bet you beat him with ease if your dps is there and the healer can heal.