I recently heard a great quote in a leadership course that will be in my head next year:
"Learn to listen as though you are wrong."
That simple statement will force you to try to see the other person's point of view, and one of two good things can happen:
1. You could be convinced that you were wrong, and can either fix it or 'fess up to it.
2. You can explain yourself in a more tactful way that will be accepted by the coach or player and avoid escalation. "Gee, if I was standing where you were, that's exactly what I would have seen. But I was at a different angle, and probably had a better look than you did. Trust me, I'm pretty sure I got that one right."
Option #1 is being strong enough to admit a mistake or a weak call, and fix a potential administrative error. Option #2 is just good customer service. If your ego can handle these options, you'll be a much better official and steward of the game.