 Don't do that. It's only going to back that person into a corner. My recommendation would be to listen, ask them questions, ask them questions that get at their underlying emotional state, how they are feeling, and always ensure that you are providing that non-judgmental space for them. Don't ridicule them. Don't shake your finger at them. And the reason why that is so important is they need the possibility to come back to you if and when they realize they were wrong.