Smells Like the Wandering Spirit

While searching a shanty town for a potential Witch, Sakaki investigates an oddly agitated man. When the man suddenly flees from him in terror, Sakaki chases after him and inadvertently causes terrified man to run into traffic and struck by a truck. An autopsy reveals the man wasn't a Witch after all; just a normal man with the scent of olives. The question remains: Why did he run when he had no apparent reason to?