"It's provably incorrect," he told NBC News.
Even though the number and value of the coins swiped from a cashier's vault at the mint match the hoard, McCarthy reeled off a list of reasons they're not one and the same:
- The mint's vault probably would have held bags containing coins from a single year with identical mint marks, but the hoard is much more diverse.
- The hoard contains many coins that were heavily circulated, but the mint would have melted down and reissued those, not stored them.
- There are 50 $10 gold coins in the hoard. Those were never mentioned in accounts of the mint heist, also known as the Dimmick Defalcation.
- The hoard's coins don't have what experts call "bag marks," which they would expect to see on coins that had been vaulted for any length of time.
- None of the hoard coins have dates after 1894, which would mean they would have been stored for six years at a minimum if they were from the mint job. "Who keeps 6-year-old inventory, especially of something that is not hard to get rid of?" McCarthy said.
Based on where the coins were discovered a year ago, McCarthy thinks they were amassed by someone doing a lot of a business in gold and who buried each can as soon as it was filled up, possibly over a span of 20 years.
An unexpected death would explain why they were abandoned — only to be found by the anonymous couple walking their dog on their property a century later.
"You can't take it with you," he said.
—By Tracy Connor of NBC News