When caught in a disagreement with someone, make them feel like you consider them honest, upright, and fair.
When you get into a disagreement with someone, it can quickly escalate into an argument if preventive measures aren’t taken. Once it turns into an argument, there is very little you can do to resolve it, as both you and the other party involved are likely to be too heated to come to a rational conclusion.
So, to ensure that the disagreement remains a discussion, and not an argument, let the other party know that you consider them honest, upright, and fair. You will compel them to act in a fair manner and you will likely get the outcome you desire.