could just be she was the straw that broke the camel's back.
In essense, not that she's necessarily too much on her own, but added onto everyone else the odds were suddenly so stacked against him that he had no hope of doing what he came for and it was best to just bail.
That and he seemed genuinely surprised she was there, and against him, so maybe it was also the shock of the sudden shift in the situation that forced him to retreat, so that he (or whoever is above him) can reconvene and assess what should be done from here.