> I’m sort of convinced that’s the author’s intent now.

The author is capable of writing with precise clarity about even the darkest subjects. IMHO, if Mr McCarthy intended there to be an unambiguous meaning, then he would have put it in the novel. he did not, therefor, it is intentionally ambiguous, for us to ponder - above I compared this to David Lynch who is known for avoiding precise explanation his films.

But that is an excellent interpretation.