I think that newcomers put themselves in jeopardy because they hears so much about "rigorous honesty" being crucial to recovery. What is usually not explained is that rigorous honesty means with oneself first and foremost, and then maybe with a couple very trusted individuals...it does not mean spilling the beans to every Tom, Dick, and Harry sitting in a folding chair. That said, if one were to spill the beans, then it would be logical for a newcomer to assume that a meeting which stresses anonymity would be a safe place to do so. Unfortunately, under the circumstances you are describing, that individual may well be worse off than when they came in.
My dear friend Legna...I don't have to tell you my suggestion for the snitch. Suffice it to say that my solution likely doesn't fall anywhere on the 12 step continuum...not even close
Xo