Describe the last time a person at work became irritated or lost his/her temper. What did they do? How did you respond? What was the outcome?

This happened during one of the performance appraisals.

One of my team members rated his work highest and as a manager when I highlighted and gave a lesser rating, he didn't agree and became agitated/lost temper supporting his rating.  

I showed all the evidences for the lower rating which he couldn't deny and finally agreed.