Ha Jin criticizes communist China through his depiction of Mr. Chiu's unjust arrest and detention, as well as his recurring illness. Early in the story, the setting is established with a reference to a "concrete statue of Chairman Mao." After Mr. Chiu has been locked into his cell for the night, the narrator says he isn’t afraid because the Cultural Revolution is over, meaning all citizens are considered equal before the law. In the communist regime, this should include the police, too.

In theory, Mr. Chiu ought to be safe from unjust treatment and handled fairly and equally, but that is not what happens. He is arrested and imprisoned when he has done nothing wrong, and he's expected to confess to a crime he didn't commit. The ideals of the Cultural Revolution and communism, then, have not been realized. Even though Mr. Chiu himself notes that the Cultural Revolution's ending should provide some egalitarianism, this is merely not the reality.

In fact, Mr. Chiu's health can be interpreted as a symbol of this communist political system as well; he literally becomes gravely ill as a result of his treatment. His hepatitis seems to have been in retreat previously, representing his life on the up and up. Mr. Chiu has been recently married, is employed at a university, and working toward a paper publication deadline. He and his wife are wrapping up their honeymoon after two weeks. In general, these factors indicate that his life seems to be going well. When he is wrongfully imprisoned, his illness returns with a vengeance. The government—in the form of the police—has caused his illness to rear its ugly head. It is especially symbolic that the illness was heightened when Mr. Chiu rose to sign the papers confessing his nonexistent crime. He faltered on his way up as if it were the final nail in his moral coffin. Though it is unclear if his health improves in the long term after the imprisonment, it follows that his mistreatment is a linkage. 

Irony runs through the story. The police arrest Mr. Chiu for disrupting public order even though the police officers who spilled on him were in the wrong. They accuse him of sabotage, though this is not the case—yet. When Mr. Chiu spreads his hepatitis through the population, he becomes the titular saboteur at last. 

The concepts of freedom versus imprisonment are overtly discussed in the story. Of course, there is the matter of Mr. Chiu’s physical imprisonment and subsequent release. On a metaphorical level, however, Mr. Chiu and the general Chinese public are not “free.” They must operate under the fear that the government has instilled. Through the manipulation of Mr. Chiu and the bystanders, the police have essentially deemed that no one is safe—even the truth can be corrupted. It becomes a lose-lose situation because honesty means little to nothing to the police.

This unfair, damned if you do, damned if you don’t scenario causes him to act out spitefully and irrationally against people who have done nothing to him. Purposely spreading his contagion around the city is the only avenue of action that Mr. Chiu sees fit to act out. By doing so, "Saboteur" seems to suggest a warning: communism will result in the mistreatment of people, failing to offer the equality it promised, and this will lead to violent acts of rebellion.