"Person A was under NDA, so we got them to pass their knowledge to person B, then had person B do the work - that's clean-room, right?"

Judges, as far as I know, do not generally take kindly to such arguments.

Wouldn't B's publication of the information make it by definition no longer a trade secret? It is now public knowledge, regardless of whether the current or former engineers might be liable for the original leak.

Any other interpretation would mean trade secrets have essentially infinite protection/NDAs apply to all of humanity.

> NDAs apply to all of humanity

The NDA doesn't apply to people who haven't signed it, but copyright law does. If you know the material you're receiving is under copyright (eg proprietary source code), and you publish work based on that copyright material, the fact that it's now widely available is not an effective defense against claims of copyright violation.

Person B in this scenario hasn't violated the NDA, but they could be sued for copyright infringement.

The point of a clean-room implementation is that the only thing passing from A to B is a detailed specification written from scratch, because functional details cannot be copyrighted.

Which I think you know, so I don't understand your argument.

You said in another comment "However, this specific thread is about the scenario where an employee has inside knowledge and is passing that knowledge on to the implementer."

It being proprietary and/or secret information doesn't affect the copyright of the clean-room output. If there's trade secret implications those are worth discussing, but as a separate issue.

So what if person a and person b are unrelated and person b found it on their own? There are countries in the global south that never had an industrial revolution and don't speak English and never had factories for export nor made anything in a factory industrially that isn't building material and food and maybe fuel for local consumption so they've never had an IP infringement case

> what if person a and person b are unrelated and person b found it on their own

That's what's referred to as a "clean room implementation" further up the thread.

However, this specific thread is about the scenario where an employee has inside knowledge and is passing that knowledge on to the implementer.

Legally speaking, a clean room implementation has much better defenses from claims of copyright violation.

I mean person b found the work of person a on their own