So, I found him in my emoush raid as well. I did not have the task from Bianca Galbraith called "A Goblin's Escort" which this is supposed to be tied to. I need to do another emoush raid in a few days so I'll test this out further. What I found was the above chat info, but we did not attack Higglin. Instead we said ready, and escorted him to the "Apprentice Foreman", whom we then hailed, and he took us to the "Delve Foreman". We hailed him, and he took us to the Elder Foreman. At this point the task failed on us, as the only chat message we got from al of them was: "I don't trusts you! Get out of here before they see me talking to you!"
Higglin got hit a few times, though never enough to be close to death, however his chat message does state that "If I get hurt it's all over for you.." so I wonder if you need to pre-clear all the mobs first so there's no chance of him getting hurt during his walk. I'll see what I can determine next run through.