Curious that someone who thinks "of" and "have" are the same word can come out with phrases like "greater vernacular pragmatism".

So you found it then? Well done that man! Now, stop trying to be smart and go back & read what I said back then and try to get your brain around a notion in which the pragmatics of vernacular usage determine the grammatical sense of the word rather than the pedantry you otherwise seem so fond of. Think of it as Linguistic Folklore - which is to say the way people actually use language as everyday living phenomenon rather than the rules of grammar which we're born with a complete preparedness for anyway.   

It's a matter of simple phonetics, with could have sounding very like could of in certain dialects - cuduv - so when a person writes it, they naturally write could of. The pragmatic intention is obvious, as is the derivation, in which, in this context, of does indeed mean have.

Folk? Pedantry? Death of vernacular diversity? Perish the thought!