I think by not allowing yourself to get sucked into a public confrontation is one step. Let it go, until you can discuss the situation with the other person privately. Any type of hostile environment affects everyone. You can feel and sense negativity. It causes more anxiety in patients and staff, breaking down confidence, negates the healing environment. If this person is the RN, who is perpetrating this and there is a manager or supervisor available I would bring them in on the conversation. I would also have an unbiased withness in the room during your private discussion, otherwise it comes to you said, they said.