Premanand Maharaj Ji
What should I do when both sides in a dispute believe they are right and I fear committing a sin?
Let a righteous person decide
When your own decision cannot settle a dispute, make a righteous, knowledgeable person the judge and both sides accept his decision. Our disputes are tied to self-interest, and following scripture's command and the words of saints is the way to go.
Make a righteous person the judge. When talks between two sides reach no decision, accept as judge a righteous person who has right understanding.