There is no miracle on this fight.. it's a gear check. I checked your longest attempt.. and you have some DPS below 100k dps, which says they are either undergeared or are not doing the fight well (not using the leg buff properly).
We 3 healed it, and our overall dps for the fight was 700k DPS. You guys 2 healed and are at 640k DPS, so you need to find a way to add 60k DPS to your group.
Also yes we 3 heal, but disc/monk, we're doing 50k DPS together. If it helps here is the log of our first kill.. and we really brought a backup once and we started to hit the enrage, so the gear is very important on that fight. Also, at 33% the healing requirement is a joke, so it's another time to make sure healers are taking pheromones and dps can focus on dps..
http://www.worldoflogs.com/reports/r...?s=8348&e=8769
Also, make sure your monk knows what to do, for some reason, he's really not healing this fight properly. I have never used soothing mist and enveloping mist in that fight.. it's a jab/jab/uplift fight, while moving to the legs to benefit from damage buff (so more healing).