Handling collaboration requests from the authors of double-blind reviewed papers (after submitting the review)

Question

(I apologize if this is a duplicate, but I was not able to find any similar case on AcademiaSE)

I am finding myself in a very odd and unpleasant situation. The subject is "ethical" peer review in Computer Science.

I am a sub-reviewer of a conference. As such, I was assigned some papers to review (in double-blind format); however, for the papers I am assigned, I am able to see who the other reviewers are, and also their reviews on these papers. As a sub-reviewer, my name does not appear on the listed TPC of the conference.

Among the papers I am assigned, there is Paper A. I reviewed this paper and I liked it, albeit it had some flaws. After submitting my review, I was able to read the other reviewers' remarks - some were positive, some negative. My (positive) comments allowed the paper to pass the first round of review.

Now the problem: I received an email from a Researcher X who I did not know, asking a collaboration proposal; the email had Paper A in the attachment. Apparently, Researcher X found it relevant to include a proof that they're working on something to corroborate the collaboration request. I would be very willing to collaborate with X, as I consider their research group to be strong.

You can easily understand my awkward situation: what to do?

Things to take in mind:

• My review has already been submitted and evaluated. Hence, I cannot turn down the review-request.
• I can turn down the collaboration request, but I would lose a significant opportunity for my academic career.
• Even if I warn the TPC of the conference to "retract" my review, I was still able to see the reviews of the other reviewers (as well as their names).
• Moreover, my review has already had an impact on the future of the paper.
• My name did not appear on the TPC list, meaning that Researcher X acted in good faith.

Answer 1

Given the timeline there is no ethical concern. You don't need to retract your review and you can agree to collaborate.

However, you should decline to review paper A if it goes to a next round. And in the short term you should refrain from telling the authors of your review. I don't see an issue in telling them later, after a final decision is made by others.

You might want to inform the program chair of the situation, giving the timeline. I doubt that they would have any complaint nor any reason to act.

Given what you say, the events seem to be entirely independent. Serendipity happens.