How does Maupassant show the characters' suspicion of one another?

In the short story "A Piece of String" by Guy de Maupassant, most of the suspicion in the story is focused on Maitre Hauchecorne, a peasant who has arrived in Goderville to sell his wares at the market. As a salesman, he is already under suspicion as a possible swindler. After being spotted picking up a piece of string from the ground by his nemesis, Maitre Malandain, he is accused by Malandain of finding—and failing to return—a black leather pocketbook. When Maitre Hauchecorne is questioned by the mayor, he grows more and more agitated trying to prove his innocence:

The peasant, furious, raised his hand and spat on the ground beside him as if to attest his good faith, repeating:
"For all that, it is God's truth, M'sieu le Maire. There! On my soul's salvation, I repeat it."

Still, he is not believed. Even when the purse is returned by the market gardener, Maitre Hauchecorne is not absolved by the townspeople. As Maitre Hauchecorne recounts his story to anyone who will listen, he never receives the reaction he desires. Many of the townspeople have a joking manner as they listen to him. Many laugh outright. One punches him in the stomach and calls him a rogue. Another demands he leave the tavern at which he's eating dinner.
Ultimately, the constant suspicion and doubt drive Hauchecorne to his grave.