Maybe I'm a bit frazzled today coming to grips with the knowledge that everything I've ever though about Barbara Gordon was wrong, but this story finally makes sense to me: Barbara Gordon survives because her enemies, when faced with the most impotent gestures of retaliation, give up. While Cass could easily slice through that rope and continue pummeling Barbara's avatar, the smug look on the avatar's face, proud that it accomplished anything, is all it takes to have Cass stand down.