Looks like @throw6606 was right: https://news.ycombinator.com/item?id=24533937. Does anyone know the status of https://ai.facebook.com/blog/paving-the-way-for-software-20-...?
(Missing the -with-kotlin at the end)
This kind of tactics has been used since the beginning of time.
There was no way to produce a hard evidence, and everyone knew that.