John McPhee has a series of great books on Geology, where he traveled I-80 across the country with a series of prominent geologists; the first published was "Basin and Range" which dealt with Nevada, and he traveled with Deffeyes.
Deffeyes didn't strike me as a loony from reading the book. There's not a single mention of petroleum anywhere in the book, though. Actually, in the book, Deffeyes spends much of his time looking for old abandoned Silver mines so he can set up a portable refining facility to extract silver from the tailings...apparently, he made quite a bit of $$$$.
Ex-professor conjures up he was fired, where as retired professor conjures up that he left on good terms. There's a Latin term for retired professors universities use that I can't think of right now.