Needs to be looked at. The npc is obnoxiously powerful and the reward for a group that kills him is absurd and hidden behind locked unbreakable doors. The xp reward is also pretty terrible.
On the death those door are suppose to open up. All three times I've done this quest that's been the case. That said the loot table for this is strange, The very first time I ran through the reward was stunning, but the second too times it was less then I have seen from delivery quests.
If lag or something stops this, maybe the boss should just drop a key for them?
It's an intense fight, to be sure.
I've seen pcs do that quest twice, and not a scratch on them. Doors shouldn't be closed though, so I'll have a look. I'll give people a bit more time to try it out, and see how it goes before altering it. And don't expect high xp if you do it at lvl8.