I've been running Ajul-Nerub as much as I can trying to get the essence of gossamer trinket like a good little druid, but I swear the 2nd boss has to be one of the buggiest in the game.
I've only gotten guildies brave enough to run it a few times and of those 3 times twice Hadronox was bugged. The first time the adds never stopped coming and the boss never came up. We googled the issue and found that waiting outside the instance for 5 minutes resets the boss so we were able to kill the boss after doing just that.
Last night was a much worse bug, the trash actually killed the boss. I was totally not expecting that or I would of tagged the boss so I could loot it. So we never got to kill Hadronox at all and just went on and killed the third boss. Even checked back after the same group went to violet hold to see if the boss respawned, but he stayed dead.
It is almost as if some unseen force was trying to deny me my tanking trinket!