Heh, the original being entirely vibed had me thinking of an interesting problem: if you used the same model to generate a specification, then reset the state and passed that specification back to it for implementation, the resulting code would by design be very close to the original. With enough luck (or engineering), you could even get the same exact files in some cases.

Does this still count as clean-room? Or what if the model wasn't the same exact one, but one trained the same way on the same input material, which Anthropic never owned?

This is going to be a decade of very interesting, and probably often hypocritical lawsuits.

right. that's not what people are doing here though, at all

in a typical clean-room design, the person writing the new implementation is not supposed to have any knowledge of the original, they should only have knowledge of the specification.

if one person writes the spec from the implementation, and then also writes the new implementation, it is not clean-room design.