I don't know that outcast rating would have anything to do with it, since Degannwy's NPCs generally don't have a problem with half-orcs, calibans, drow and whatever other outcast races trigger the Garda. The only time I've seen Degannwy's NPCs hostile someone randomly was years ago when Kith and Legos were having a sparring demonstration. Soon as they started fighting, every NPC in sight attacked Legos. Is it possible you did something similar?