Among those who conspired against Lee Chum Foon and framed him as the Plum Blossom Bandit, some had very clear motives. Lung Siu Wan viewed Lee's return as a threat to the domestic life he had established with Lam See Yam and their son after Lee left for the hinterlands. Lam Sin Yee wanted revenge against Lee for rejecting and humiliating her (and being a thorn in her side in general). Yau Lung Sang was jealous of Lee because he seemingly stole Lam Sin Yee's attention from him and then humiliated him in a duel. I don't quite fully understand Chiu Jing Ngor and Tin 7's stake in the conspiracy, however. Ostensibly, it's to collect the monetary reward and Lam Sin Yee's hand in marriage for capturing/killing the Plum Blossom Bandit, but there seemed to be some serious personal animosity between Chiu/Tin and Lee Chum Foon beyond the rewards they coveted. Moreover, if the reward was all they wanted, there were easier targets to frame than Lee Chum Foon.