My friend works at a well-known tech company in San Francisco. He was reviewing his junior team member's pull request. When asked what a chunk of code did, the team member matter-of-factly replied "I don't know, chatgpt wrote that"
I asked one of the "AI" assistants to do a very specific algorithmic problem for me and it did. And included unit tests which just so happened to hit all the exact edge cases that you would need to test for with the algorithm.
The "AI assistant" very clearly regurgitated the code of somebody. I, however, couldn't find a particular example of that code no matter how hard I searched. It is extremely likely that the regurgitated code was not open source.
Who is liable if I incorporate that code into my product?
I've no idea whether in this case it directly copied someone else's work, but I don't think that it writing good unit tests is evidence that it did - that's it doing what it was built to do. And you searching and failing to find a source is weak evidence that it did not.
If you change the programming language, the unit tests disappear and the "generated" code loses the nice abstractions. It's clearly regurgitating the Python code and "generating" the code for other languages.