“Is a lawyer allowed to break client-lawyer privilege if his client admits to a felony or other crime?”
An interesting point. The lawyer represents the client in an adversarial system. If the client tells the lawyer, “hey, I did it,” and the lawyer says, “hey, he said he did it,” the lawyer can’t represent the client in the legal system we have. As I recall, lawyers are allowed to lie.
Originally, our legal system was under the church. It still has relics of its past. The twelve people on the jury each represent an apostle, for example. But our legal system was taken away from the church and made secular. The laws, for a long time now, have removed many of the traditional protections the church enjoyed. I believe that the relationship between confessor and priest has been legally changed in some states. I recall reading that now priests are required to report child abusers, for example.
My guess is the priest is toast. If it turns out that the girl lied about the confession in an attempt to extort the church, he’ll go to jail for no reason.
Lawyers are not allowed to lie. Lying as a lawyer will get you disbarred, or at least in mucho trouble.