Complex sentence: Caught off guard by the hostility of Angela's response that she would be a commandant of a concentration camp, the mother shoots Traunitz in the neck--which turns out to be only a superficial flesh wound.
Split into simpler sentences: Caught off guard by the hostility of Angela's response that she would be a commandant of a concentration camp, the mother shoots Traunitz in the neck. However this turns out to be only a superficial flesh wound.