I don't think that we can ever completely trust the narrator because she is not purely objective/ descriptive but also sets a mood. After having witnessed what just happened to his Honour Guard, Orpheus might very well be in such a rage that he is after his enemies' blood (I can't remember the exact text) - but that doesn't say that he wouldn't have cooled down and listened to reason if we had freed him. But we haven't been given the information that he would listen to reason and would do anything to stop the Grand Design yet, we are simply in a highly confusing situation with two strangers one of which is furious and in shackles.
When I first got this scene I had enraged Vlaakith but didn't have Lae'zel in the group, so the githyanki were hunting us but we didn't have Voss's trinket. I had at first thought the githyanki attacking the camp had been send by Vlaakith who after all wanted the person inside the prism dead. So it was all especially confusing.
