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.

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