There's a whole bunch've stuff that COULD have set them off, but.. I dunno if that's actually it
- I ran into a couple fighting a mammoth while I was in werewolf form and they attacked me. Though I changed back in front of them and yielded and they seemed to be ok with that, putting away their weapons and laughing about my nudity. Even going so far as to offer me combat training and Aela who was also there turned in a quest. So all seemed well on that occasion.
- I just came back from an absolute massacre in Solitude with about 11 guards killed. (Falk Firebeard sent me an urgent missive to travel to the blue palace. Was a trap though the guards just wanted to kill me!), I don't see why the companions would hate me for being hated by solitude authorities though.
- I did transform in front of Aela once and she attacked me (How could you NOT know I was a werewolf dummy!), but she also accepted my yield. But Aela is one of the few companions who is still friendly to me.
...oh well, you know what they say. You either die a hero or live long enough to see yourself become the villain



