Players do not have any way to enforce their made up authority into others. The only authority a law enforcer player character can have is that given to them by those involved in the scene. If no one agrees OOCly to recognize him as a law enforcer, then he effectively is not an authority as far as those people are concerned. Which means there cannot be any 'real' consequences unless the players agree to it.
As usual, the key is to communicate OOCly anything that might cause lasting consequences on other people's characters.
As usual, the key is to communicate OOCly anything that might cause lasting consequences on other people's characters.