My logic is: - The stuff appears to be in the ground. - The new...

My logic is:
- The stuff appears to be in the ground.
- The new machinery will make the mine more profitable than past attempts (and although past McGuffins have promised to do the same, we know the economics of this machine and what it can do)
- The current management may be incompetent and unethical but they want more diamonds. And seeing they appear to have the means to do it, I have a certain degree of faith they'll bash their heads together until they find the right expertise to tell them where to dig.

I hope this addresses what you were asking. Please call out on my flawed logic if anything jumps out. The largest threat in my view is a hostile takeover from management.