Every so often (or possibly everysooften) you come across a proof-reader or copy-editor who is a failed writer and thinks that, having been unable to make a success of their own book, they'll appropriate yours. I got one once - just once, out of 40-something books - and I returned the proofs unmarked, and complained about the degree of inference to both my agent and my publisher.
The publisher, far from leaping on her high horse, was most apologetic and undertook to edit the text herself. Every suggestion she made was valid, and I think I accepted all of them. And there were pages and pages without a mark on them. If you're a competent writer, that's what a copy-edited text should look like.