Unfortunately, people should not be so fast to tell guys with metal detectors where they lose their valuables. There is a thread right now on the beach and water forum where people talk about adds up on the internet, "hey I found your ring, just tell me where and when to identify it," which is totally bogus, but after some poor lady comes along and says she lost it at such-and-such a beach, the guy goes out, gets the ring, and tells the lady "nope, haven't seen it yet! Sorry!" I hope I'm wrong but this guy's ring is probably already in a scrap pile.
Trust detectorists who can show evidence of successful returns, like pictures or maybe a small story in the local paper. Don't just go around telling anyone where you lost something so valuable...