To me it's sort of a toss up between these two scenarios. Implicit grant that has never been tried in court vs explicit grant that only gets revoked if I initiate a patent war?
In both scenarios you have a patent grant before going to court over Patents. The difference is that, in one scenario, you no longer have a patent grant once you go to court. In the other scenario (where PATENTS file never exists), you may still have the patent grant after court.