For all we know, it was made by a person/bot/process authorized to publish to an official Google repository[1].

It may have been accidental, sure[2]. But is there a basis to claim unauthorized action?

[1]: https://news.ycombinator.com/item?id=40505708

[2]: Reminds me of “Night of the Living Dead”, which accidentally became public domain; source: https://en.m.wikipedia.org/wiki/Night_of_the_Living_Dead