Seer Kwon is the despicable man Sonmi sees throwing a living fabricant off a bridge. His behavior is reminiscent of the kind of slave owners who wantonly abused and killed without any regard for life. Seeing this heinous act is one thing among many that convinces Sonmi to fight for the freedom of fabricants worldwide.
Sonmi doesn't see Seer Kwon's act as an isolated incident: "Only the corpocratic pyramid that permits fabricants to be killed so wantonly" (6.1.182). She blames the entire system, and as a result wants to bring it down. Seer Kwon only shows up for two pages, what he does shows us that everyone's actions have an impact, often in unexpected ways.