It's really just a matter of did you "survive" or not. Have your parter take a highlighter pen and put on all white close, and have them attack you anyway they want. If you disarm them without being marked on vulnerable points, you "survived", but if you get shredded at the danger zones like the neck, stomack face, arteries, etc., then you "died" and failed. It's very black and white.
Member of DaJoGen MMA school under Dave Hagen and Team Chaos fight team under Denver Mangiyatan and Chris Toquero, ran out of Zanshin Martial Arts in Salem Oregon: http://www.zanshinarts.org/Home.aspx