If you don't want to be DF'd DO NOT tell ANYONE your reason for leaving. If asked prying questions just reply, "I do not feel the need to discuss that with you, it's personal." Once you start talking, you are at risk of DF'ing.
Be careful, some demented elders will try and trick you. We have had this done to us. We know exactly what this person is up to. He wants us DF'd . He thinks he is slick. We say NOTHING. It pisses him off to no end. It has been quite amusing to play this game with him.