This whole mess was a tough lesson for everyone involved. My husband learned that “trust is fragile” and that he should never “lend” family heirlooms again. He apologized profusely to me and to his mother, who eventually forgave him. I learned that when people “show you a tiny crack in their character,” you shouldn’t ignore it.
As for Tariq, he got his comeuppance. He was arrested a month later for a string of small-time scams in a nearby city. It seems that karma does a good job of evening the score.