This is why I mentioned the other LL barrel roll. It is possible that the situation may have been recoverable in a previous aircraft with which the pilot was more familiar. It also may well have been the case that, after passing the inverted position, the aircraft was continuously thereafter outside ejection seat limits. They aren't a magic wand, and the zero height - zero speed seat depends on zero sink rate and zero bank angle, neither of which are present in the second half of a barrel roll.