If the expression, "the written and oral Torahs are the words of God delivered to Moses on Mt. Sinai" cannot be read literally, then what does it mean? I believe the Rabbis of the Talmud are pronouncing the deepest respect possible for the received tradition.
One of the reasons that the language of reverence needed to be so powerful was precisely because of the radical innovations which the Rabbis themselves were facilitating in the development of Jewish law. The Rabbis were masterful agents of change.