I agree that the average human being will revert to type, or worse, in such scenario and it is for this very reason that emergency and military forces the world over spend a lot of time and money training so that dealing with high impact stress such as this does become second nature BUT younever know how good that training is until the real thing happens. That's why their training develops over time too, it's based on feedback (debriefing) form real events.
PDR1 sounds harrowing, glad you (finally) got out, I'm sure the rest of us can;t imagine what you went through