It's interesting (and he's certainly not the only one to see it similarly), but whether you buy into it or not doesn't strike me as too important. "Death" or not, it's still a physical character interacting with other characters. Can't see how reading it that way could ever be misinterpreting anything. (Unless he is saying that Chigurh never existed at all, and was symbolic of death, not representative of Death, in which case I don't get, or buy it. I also haven't read the theory in depth though.)