This is precisely an exception to the rules regarding cases with 2+ Game Over (GO) in a single playthrough. It doesn't apply here. In the game between Gomunguls and Darkello, there is only one instance of GO.
But I also wrote that this violation is not obvious and is a result of an error in the rules, as in similar situations (multiple GOs or a GO shifted deeper into the respawn) Darkello's action would be legal.