Given the existence of an ore body there are an astonishing number of ways a single, or even a few holes, can miss it. That's why JB has not drilled before.

The difference, now, is physical evidence allowing greater focus than was possible with only vegitation samples and geophysics. It's still a big risk to drill only a few holes, even if JB's theory is correct. But circumstances make it worth the risk vs. doing nothing.