Murder/pedophilia/physical abuse need to be reported (don't care about robbery and such that aren't physical in nature). Let the laws of men exact punishment for crimes against others and let God worry about whether or not they have been saved by the blood of Jesus - there should be no conflict with this line of reasoning - unless one wants to make a "sharia" type claim where the religion overrides everything else....
The problem is that “thought-crimes” are encroaching more and more into our legal system and growing much broader scope.
Scenario: A man comes from a fight in which he injured the other participant. The other man happens to be gay, or of some other hyphenated group. At one instance in the course of confessing he refers to the other party as a “lousy faggot...etc”.
It may be generally agreed by witnesses that the other party began the fight, and that the man acted in self defense. But police or prosecutors may decide to go fishing, and demand that the priest provide his notes on the “session.”
If they find that the man used demeaning language ,prejudice and animosity can be shown. They decide to prosecute and threaten to put the priest under oath. The man will likely be found guilty of a hate crime, or cop to a lesser charge at considerable expense.