Not so. OS applies when teh ball was last played or touched by a teammate. The deflection off the attacker does not alleviate OS for the player on the GK's team, as it was only a deflection. So in our strained and farfetched hypothetical the last play was by the GK (meaning any teammate of the GK who was in OSP at the moment of the punt may not touch the ball until touched by an onside teammate or played by an opponent), and the last touch was by the opponent of the GK (meaning any opponent of the GK who was in OSP at the moment the ball was deflected may not touch the ball until played by an opponent of the GK or touched by at teammate of the GK.)