And this is one of the reasons some people are up in arms about Anthropic's recent inclusion of watermarking against anything Claude models touch. It will even take human-generated code that it works on and apply watermarks to it which can be then used to prove it was AI processed and perhaps invalidate any copyright on even human-written code.
But even if it wasn't watermarked and someone later found out or a whistleblower revealed that the code was A.I. generated it could lead to the loss of copyright.
Imagine what this would do to a product like Microsoft Windows or Microsoft Office!