Letting to save face
Allow your report to save face. When somebody makes a mistake, she's usually the first to know about it, so you don't have to rub his nose in it. Help her avoiding the distress and discomfort that accompanies a mistake. Do not criticise the other person's caracter, personality. Stick to talk about the behavior as you see it. Assure her that she is not under attack. Listen carefully, ask open ended questions. Keep it brief. People appreciate your benevolence when you overlook minor misdeeds. It creates long-term goodwill that pays off for you.