I can't speak for his blog writings (since I have only read a few articles), but I have read his book on Nozick and am almost done with his book on Aquinas.

• Show that some medieval philosopher said the jargon claim was nonsense.

• Accuse the original atheist of spewing nonsense and being unaware of the true philosophical underpinnings of Christianity.

I have no reason to doubt your claim, but it seems plausible that he is right in this case (if, in fact, he does so accuse atheists in this way). Why? Because I had 4 years of Bible class in high school and studied philosophy of religion at university and yet still only understood the straw man versions (most likely unintentional straw men, mind you) of the arguments made by "some medieval philosopher", or had any idea about the philosophical "underpinnings of Christianity".

It wasn't until I got interested enough in the history of science to actually bother to read primary texts (in astronomy, alchemy, and "physics") that I was able to get my mind situated in such a way that I could look around at the world from within these alien Medieval paradigms and see that some of these claims weren't just silly bullshit.

Anyway, if it takes such a roundabout sequence of obscure studies to even begin to make sense of this stuff, it is no wonder that modern atheists (or virtually all Christians, for that matter) have trouble getting it right.