At the beginning of LUK SIU FUNG: THE DUEL, it seemed that Beijing land barron Dao Tung Heen would be a major figure in the conspiracy surrounding Sai Mun Chui Sheut and Yip Goo Sing's duel. Dao had big money (his entire fortune) invested on Yip defeating Sai Mun in the duel, so it stands to reason that Dao would do anything within his power to help Yip win.
But halfway through the story, the character and the subplot involving him and Luk Siu Fung's friend Lee Yim Bak just disappear. We never learn what involvement Dao actually had with the cabal of Yip Goo Sing, the Southern Prince, and Eunuch Wong that tried to overthrow the Ming emperor. Moreover, since Yip Goo Sing lost the duel, then Dao lost his bet (although his betting partners, Lee Yim Bak and Taoist Goo Ching Fung were both dead, so there was nobody to collect from him).