Thunderhead glitch?

Sorry if this has been posted before (did a quick search, didn't find anything) but this doesn't seem normal...



After I cleared out the fort, Jalis went up to the throne...then back to the center of the fort and stayed there. Some enemies passed him and went up to the throne, but enough went to the center to eventually cost me the mission, cause apparently he isn't infused. He went off to fight a jade bow, and by the time we killed it it'd put spectral agony on him and mhenlo just watched his health steadily drop.