Language Log: Is Mark Steyn guilty of plagiarism?

I described the facts in an earlier post. It seems clear to me that in Steyn's 550-word discussion of Dan Brown's style, he took the terminology, most of the basic ideas, all of his three examples (in order), a couple of turns of phrase, and his punch line from one of Geoff Pullum's Language Log posts. He credits Pullum by name (though he gives no link or any other sort of source citation) for the term "anarthrous occupational nominal premodifier", but not for the rest of his borrowings. I promised to give my opinion later on, and this is a first installment.