In Gu Long's novels, elite swordsmen such as Yin 13, Tse Hiu Fung, Sai Mun Chui Sheut, Yip Goo Sing, Ah Fei, and Ging Mo Meng tended to be killers. For them, victory was almost inevitably their slain opponent's blood at the tip of their swords. Rarely did any of them win a duel without killing his opponent.
What about Dook Goo Kau Bai? He won all those fights (supposedly): do you think he tended to kill his opponents (which might explain why there was hardly anyone around to propagate his legend) or do you think he spared them?