Not the least bit true.
If the priest was having a conversation at a food court in a shopping mall and was overheard by passersby, the secular authority would have every right to dispute a claim that he was hearing a confession. The church simply does not have plenary power to say what constitutes a protected conversation for the purposes of a secular law.
straw argument. you know exactly what context confession is being talked about. in church, with a private confession to a pastor or priest.