1. we are not talking about random code files, but a very special case.
2. it has become apparent that the elements copied are NOT subject to copyright.
3. It's fine and in the spirit of what the authors meant, and probably the GPL too, but the first part should be more than enough.
Your position is very, very weak. You can only argue about legal subtleties, and even there you're not in firm ground. Why do you insist in spreading the FUD?