Most of the people come to a conclusion - while handling a dispute - listening to one side of the story or, to both the sides but believing the one coming from people whom they are emotionally attached with.
Don't be a fool, to be blackmailed emotionally, if you wish to follow the path of neutrality and justice.
So I suggest: Never blindly trust even the most trustworthy but verify the content of dispute, before taking a call on the issue and releasing your opinion.