Not only is there a lack of credible evidence to "prove" that it happened, there is a lack of evidence to even SUGGEST that it happened.
The current evidence that can be examined today SUGGESTS that "perhaps" something MAY have been buried on Oak Island during the 1700's. SUPPOSEDLY (it is only based on un-corroborated statements) - A depression in the ground under a tree with a "groove" worn in a limb above the depression (as from a rope - NO "block and tackle was found hanging) indicate it may have been used to lower something into a hole beneath. The description of the tree size ("could wrap one's arms around the trunk and touch fingers" - approx. 22"-24"), if it was an oak, this indicates the tree was approximately 120 years old in 1795. Contemporary stories of that era state that it was a "pirate treasure", probably the most reasonable explanation, though also without any evidence. That the "Money Pit" could contain "something else" never came up for another century, and the "evidence" that supported these new stories is not known to have existed prior to the stories, either, although the "discoverers" of this "evidence" CLAIM it is older, even ancient, but for inexplicable reasons, this "evidence" cannot be produced, only "reproductions", "translations", or "recollections".