You can pretty much tell who wrote a supposedly anonymous review of a scientific paper. Just look at the papers the reviewer cites. Reviewers very often cite a whole bunch of their own papers and say that you need to address/acknowledge the issues raised in those papers, etc. etc. This is a rather cheesy way to raise the citation count of one's own articles, but it is quite widely practiced.
Editors these days mail out the complete set of reviews to all the reviewers at the same time they send them to the authors. That is how I found out that someone had essentially stolen my identity in a review -- their review was full of citations to my papers. Worse, their final recommendation was to reject the paper, and the editor actually did this.
I am tempted to email the author of the paper -- he is a sort of acquaintance -- and deny writing that review and say this reviewer was stealing my identity by peppering his negative review with citations to my papers!