I took the time to read that document a while back and it almost certainly isn't the correct guy. At the very least it provides 0 evidence other than concluding that "he must be the guy" due to his name, country of origin and programming background.
A quick web search suggests Denis Petrov is not at all a unique name. Just because on of them wrote a somewhat feminist thought on a blog in 2004 and another forked a... let's call it "satirically feminist" project on GitHub does not in any way suggest they are the same person.
https://ru.wikipedia.org/wiki/%D0%9F%D0%B5%D1%82%D1%80%D0%BE...
Pretty much anyone who has made any kind of commit to an open source project has that badge.
edit: it's incredibly naive of them to immediately trust the WHOIS results. i can say from experience that these are never checked