It appears another "gigaleak" has gone down, involving Nintendo. According to sources online, it appears that Game Freak has been hacked, resulting in internal data from the company being leaked to the public. Those involved in the hacking community or those within general Pokemon related groups...
They can see how it’s done and code their own thing. They don’t have to cut and paste the code, just know how its done.
Cleanroom RE is how you prove that’s what you did to a court. The point is to avoid into a courtroom with Nintendo at all, making the point moot.