When I'd read it the first time, my interpretation was that a player could
deliberately place the king in check and force the opponent to capture it,
but that if the opponent checked the king, that check had to be lifted or
the game was lost. (ie, that placing the king in check was legal as a
deliberate sacrifice, but that if the the opponenet started the check, it
had to be responded to normally.) This made sense to me because it kept
the king sacrifice (with mandatory capture) open as a tactical option, but
a multi-move mating combination found by the opponent still worked.
But I can definitely see Glenn's interpretation, too. Would it be rude to
ask the inventor for one final clarification on the issue?