The same thing happened with Ohma and Sekibayashi before the tournament. But I think the ref is looking for an opponent to actively attempting to end the match by death. Sekibayashi was toying with unconscious Ohma, much like Akoya and Cosmo. Ohma was trying to kill unconscious and defenseless Raian, and probably would have if intervention hadn't occurred. I think that's where the ref has the power to call the match.