we had 6 dps shaman, 2 resto shaman, pally and DK.

I was kind of stunned that we couldn't bring him down. I don't think we used any fire elementals but still, we shouldn't have needed them imo.
both teams run heroics all the time. I think the dps shaman were just too weak, they are only putting out apx 1800 dps.

to burn down 2.2M points you need a higher dps rate.