A year ago we submitted a manuscript to a high-profile journal. I was a co-author. The review process for this journal is single-blind—that is, the authors do not know who the referees are, while the referees know who the authors are—and we got two referee reports, one positive and one negative. The latter seemed to have been written by someone who hadn't had time or energy to do the job properly. Using some arguments that we found rather shallow, he argued that our research findings were not significant enough to warrant publication in that journal.
Reading the negative report carefully, I noticed there a few non-standard expressions, typed them into Google, and found two of them in articles by one and the same guy, including a single-authored article, and nowhere else on the entire Internet. The guy is a prominent scientist in our field of research.
Knowing he would never want to alienate our research group, we submitted a rebuttal letter abounding in references to his articles so as to make him realize we knew who he is. To strengthen the effect, the list of references added to the revised manuscript consisted almost exclusively of papers authored or co-authored by that guy and was explicitly provided in the rebuttal letter.
We wrote our rebuttal letter politely and respectfully in order to make it look like we wanted to pay respect to him and his research achievements by citing his articles. We addressed all his criticisms in a friendly and factual way.
Our idea was that he would think, "The authors seem to know who I am, and they as a large research group are going to referee papers by my group in the future, so it's a good idea to be friendly and reasonable towards them just in case."
His second report was very short and said we had fully dispelled his concerns and properly revised the manuscript. It got accepted and published.
As time goes on, I wonder more and more about the ethical aspect of what we did. On the one hand, we used open source information to figure out who the referee is. No one told us his identity. On the other hand, we were not supposed to know.
How ethical is what we did?
P.S. I don't know whether I deserve harsh comments, but I was an undergraduate student at that time and have posted my question here in order to learn what is ethical and what isn't. I don't want to do anything unethical in the future.