The only issue I see here is a Boomkin doing only 6m dmg over 20mins. Some classes can put out well over 24m easy, monks are one of them The fact that the monk did only 16m shows he used a lot of his dps was converted into healing and if you went oom from 16m over 20m of a fight you are not going to torcher anyone over 1200 rating. 6m dmg is nothing more then dots and a random surge. Healing through 16m dmg should never cause you to go oom, I don't see anything special here at all just someone that went afk in a 2v1 game and got owned decided to come cry about it for the luls.
I don't even know how its possible for you to die in a 1v1 situation. You clearly where outmatched or decided not to heal.