There is a known story told by Rabbi Shalom Schwadron zatzal of a child in Jerusalem who went to buy candy with a gold coin he found in the house, which a passerby secretly exchanged for a lesser coin, so the public falsely suspected the shopkeeper of stealing.
There are various versions. Here’s one I found on the web:
Rabbi Schwadron’s point was to judge favorably and not get involved in disputes. Fine.
But how could such a case occur? Why wasn’t the child asked by the dayan (perhaps Rabbi Moshe Nachum Wallenstein) if he met anyone along the way to the store?!