As the safety first explains at high level VD is almost impossible because of the drag. It's achieved in dive at full thrust. So there's no need for over reaction. With AP& ATHR leave AP on the thrust will come back just monitor if not happy use speed brakes. If unsatisfied with ATHR then use manual thrust. There was another more recent TCAS event in A320 where the pilot disconnected the AP(cardinal error) and pulled the nose up causing RA. These panic reactions are the result of not knowing that it's not that serious. After control your speed series in Safety First the procedue was introduced in FCOM/FCTM.