That doesn't make sense to me, extracting/copying a firmware blob is not clean-room design. It would only be clean-room design, as the article you link to explains, if you constructed it yourself from scratch based on the functionality you understand it should have. But ok!
Such as when it's technically legal to do something as long as you do it a certain way, but the interested parties may not believe that you did it correctly and will bury you in legal discovery requests that financially ruin you or force you to stop.
Or they sue anyways hoping for a favorable ruling that changes the interpretation of the law (Oracle v. Google for a famous example of this)