I didn't realize that the google - oracle decision was just decided over fair use!

It reminded me of this: https://malus.sh/ "cleanroom as a service" - which I guess was kind of a joke, but looks pretty serious now.... (discussion back then: https://news.ycombinator.com/item?id=47350424)

But this seems to hinge on the "clean room"- is this a separate set of case law or is it related? As in, if they had been more judicious about the way the game was implemented could they have claimed it was not under copyright?