I know he did the groundwork for Git at least, you can see his own commits in the history of https://github.com/git/git; that was 14 years ago by now though, according to that.
I was a little amazed that the corruption-in-astronomy-journalism crowd thought it was plausible that any individual could have sole authorship of 850,000 lines of code in a project started in 2016.
For comparison, the Linux kernel adds something like 300,000 lines per year from thousands of contributors.
Brian does not claim to have been doing it before Juliano or Thai. He wrote the blog post to explain in layman's terms what the attack was and released his own version of the original POET tool written in Perl.
Trivia: Andrew Tridgell's techniques here catalyzed the creation of git. He applied them to reverse-engineer parts of the Bitkeeper protocol, a proprietary version control system then hosting the linux kernel. Bitkeeper CEO Larry McVoy revoked linux's license to use BK, Linus went off and wrote a replacement, and the rest is history.
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