Prove it yourself!
Meanwhile, Kristen asked for a thirty-day exclusive on the article, which is a guide to checking page proofs, and I was glad to agree to that. I'll repost it on my own blog this time next month.
P.S. In the everybody-needs-an-editor department, Kristen made valuable improvements in the article, adding glosses for the technical terms that the lay reader might not know. In other words, Kristen added value, and that is the standard on which you should judge any editor. We—those of us who are any good at this business, anyway—are not just here to pick nits. Our goal is to help you communicate more effectively.