Comment by ffsm8

Just to make sure I understand you right: the argument is that

Acteur a has a no permissive copyright

Acteur b has a non-commercial copyright on a model that infringes on a's non permissive copyright

Acteur c now can freely use it commercially, because b's copyright notice is invalid as it was never in a position to grant a permissive license

The stuff you learn on HN is truly breathtaking.

Thanks for clearing that up, that opens up a lot of avenues for future developments