Scofflaw! You should have stopped and told those nice elderly rangers that you had broken the law and deserved a citation. But back to the topic at hand, I think your battery was not dead--it was just dead enough to not have enough juice to turn the starter. But it DID have enough juice to run the ECM and fuel pump and fuel injectors (which need way less amperage than the starter) so that when you bumped it the plugs fired and you got ignition. Nice going by the way.