Did you cast "Friends" or "Charm" on anyone? There seems to be a chance for NPCs to turn hostile when the effect ends (which is intentional I think).
Intentional it might be ...
But its a little odd ...
My experience was to cast "Friends" to Astarion, when i was persuating him to tell me about Cazador ...
When i Canceled the spell, i god Astarion Disaprooves ... so far so good ...
But then sudently Gale run to Lae'zel and acused her from stealing.

And since she have almost none charisma, i had no chance except pay him to shut up.
