The independent archaeologist John Debry did not say that the silver bar it was irrefutable proof Capt. Kidd's treasure had been found, what was left out of his statement was the he also said that more scientific evidence was needed and mentioned that analysis of the wood, among other things, was needed to determine if Clifford was dealing with English oak or not. His ship, the "Adventure Galley," was built in England in, I believe, 1696. Other pirate ships are almost certainly sunk in that bay so it could also be from another ship.
There is evidence to suggest Kidd's ship the Adventure Galley was not initially built in England, but instead was launched at Castle's yard after being refitted for it's future task with the English. Prior to this it was a merchant ship without such armament. This also explains why the Adventure Galley was so poorly built, and why so soon after launching it was badly in need of new sails and rigging in just over 9 months of service. She was also leaking from the get-go probably after being retrofit with so much added weight.
The most probable birth of the ship was like many other of the East India ships of Danish origins that were pressed into service. At the time many, if not most, of the East India ships had the added ability to maneuver using oars, and very few of the English ships had that ability. And it would only be fitting, that Captain Kidds having been given letters of marque to help support and defend the East India trade routes (a task that even overshadowed the task to protect the Crown's sovereignty, which was the English Navy's burden) should have acquired the ship through East India contacts. At the time England was not in the habit of giving up one of her prized naval vessels. They couldn't, and wouldn't.
So the English Oak probably would prove the exact opposite, that it wasn't the Adventure Galley, which launched in 1695 after refitting, sailed in April of 1696, and was so badly worn by January of 1697 as to need major repairs and maintenance near Madagascar. And this was just the beginning of the Adventure Galleys woes. This was no NEW ship! If there is a way to distinguish between English Oak vs. that from Poland, and it turned out to be Polish Oak, then the chances would be greater that it was the Adventure Galley, but not proof positive. Most Danish ships used Oak from Poland regions like Vestula, or various timbers from Lower Saxony (and various other regions like Luneberger, Heidi, or Westfalia) in Germany. (Possibly they can tell the difference considering the age and circumstances, like being submerged for so long, by using dendrochronology.)
One would also wonder, towards the end of his various journeys would Kidd have entrusted his wealth and treasure to the holds of his most UNSEAWORTHY vessel? Isn't that why they kept the more seaworthy ships, in Kidd's and the crew's own testimony? It is a matter of record and fact his treasures were moved to his "Quedagh Merchant Adventure Prize" (previously just "Quedagh Merchant") and eventually offloaded from there in Santa Catalina.
Food for thought!!!