I view some of these stories with skepticism. That said, this brings up a moral dilemma that detectorists sometimes face. Do you report it, or keep it for yourself? I'm mixed about this too.
I've found two diamond rings over the years, and both were worth a lot of sentimental value, if not monies. In both cases, I was able to find the owners and return them. I was offered a reward from one owner, which I refused, but I did get a kiss of a lifetime! That notwithstanding, I wonder how I might feel (morally) if I found a cache of gold coins? I suspect (if folks here were honest) a number of us have been tempted to maintain the thought... 'Finders keeper, losers weepers'. A few quarters in the park is one thing, but a cache of gold....? Hum?