You get this when one of your teammates bleeds out before being rescued. Most likely you will get this playing the game. Be sure you save your game every time you feel the battle is going your way, AND keep a safe prior to battle if you can in case you decide to change strategy or a death.
Additionally: You can get this achievement by eating an ally that is down with Bormin, and it doesn't matter who hit him. Will pop "Tastes like chicken" as well.