"I mean, come on, he's a geologist, and is therefore replaceable,..."

That's like saying any 'ol storefront attorney can substitute for one on the US Supreme Court.  Life does not work that way considering a lifetime of specialized studies, unique credentials, and pioneering efforts in newly evolving fields (in this case, porphyry copper deposit modeling).  By the way, are you not also demeaning AW with such statements?