It's not proof that _he_ necessarily removed it, but considering it wasn't brought down by the actual repo maintainer, and that any repos created to replace it by other users at the time were taken down as well, it's a safe assumption that someone at GH did.

There's several more sources regarding this, but I'm on a terrible mobile connection at the moment. Googling around will get you a bit more info for the story.

All the sources I've seen just show the tweets and then go on to say how he went rogue and removed the repository. Seems like a really weak argument.