Unlike recent Soul Calibur games, you can earn this in 2 player Versus mode. To perform a throw escape, you must press try to perform a throw right after your opponent tries to throw you. I used Nightmare and Maxi, and with the 2P controller in one hand, I pressed the throw command (X+A, by default), and then a split-second later I pressed the same buttons on the 1P controller. It's all about getting the timing correct, so don't get too frustrated if you don't get it right on the first attempt.