Your healers need to be absolutely attentive in that fight for the tank buster. I have always loved the trial since it came out. For the moderate player it was a nice dps check mixed with frequent tank busters and healing. If you are being attentive and using your cooldowns, the healers must also prepare. I mained a SCH back at 50 and yes I made sure my tank had an adlo. If you are topped off and only dropping to 3K after a tank buster and still manage to die due to lack of healing, it might be a healer thing too.