A series of crippling bugs on this encounter denied my group the ability to complete it, despite an otherwise successful run:
1) We never dropped out of combat, and our level 56 Priest barely managed to keep us alive.
2) I'm not 100% sure on this, but I believe a second Dragonkin Elite did not spawn once we doused the second flame.
3) When I went to douse the third flame (I stood close to the wall to avoid aggro from the centre), the flame did not go out, and my Blood disappeared. The same thing happened to our tank. We were left with two lit flames, no Bloods, and no way to get more, as we had killed all of the Elites.
4) With no choice but to reset, we did, and the encounter never started again after I used my Egg.
I put in a GM ticket, but after 45+ minutes of waiting, my party disbanded. I logged out with it still open, and I'm going to sleep.