This happened to me in the Zhentarim Hideout. Was mostly just saving often in between stealthing around and stealing barrels.
Not sure if it was related or even triggered it, but I pushed Zarys off the ledge she was standing on, didn't have her aggro but she said something ('making a mistake'?) then ran off while still not being aggro, and I knocked her unconscious.
That was the only triggering of an actual conversation I had in that stretch.
