I might have not remembered that right, but there still was this time on Hokuto no Ken when Kenshiro gave a thug the biggest "no U" out there. The thug got elbowed in the face, likely in a pressure point, then tried to explode Kenshiro's head, but blew up himself.

AFAIK, there are Hokuto Shinken pressure points that can nullify the effects of other pressure points, so that could very well happen in a fight between two Hokuto Shinken users.