I didn't even think about this but..."Perhaps you should mention Harry Dresden's own spirit as an example of harmonious cooperation, there is a risk since he obviously wishes to keep it private, but you are alone here and he has just proposed a far more thorough exchange of secrets."
Crown of Eyes and Usum being there to look alongside us may net us a look at Lasciel's shadow if thats what Harry's passenger is.
I wouldn't mind just talking about it either.