If you're arguing fair user, you've already lost. That's a matter of opinion so it has to go all the way to a jury verdict. That means there's no guarantee and even if you win, you have to pay a couple million for the billable hours. You want a defense that's so obvious, the judge will throw out any case against you on the first day.
It should be so obvious that no one would even attempt to file the case
Yeah, but how about not there being a case, and not having to argue (and pay laywers and such) at all?