I'm the first one to agree you can't be defined by one event, or one circumstance, or one fleeting moment in time.
BUT! Anyone remember that bobbled snap in the 2006 playoff game that kicked us all in the gut? All Cowboy fans anyway.
Tony Romo was the holder for the field goal kicker back then. The Cowboys were about too win the Wild Card game at Seattle, all they needed was a field goal as time expired. It looked promising cuz it was such a short field goal, like 19 yards. A chip shot. Cowboys fans were already packing their bags for the next round of playoffs in Chicago. And then the snap.