Humans are fundamentally profit-driven animals. As long as they are animals, they find it difficult to escape instinctual tendencies. No one in this world can achieve absolute rationality; often, when faced with choices, they opt for the option that benefits them the most.
An unfortunate person, saving himself, also saved the reputation of the Sabin City Tax Bureau, allowing all law enforcement systems to regain some points. Johnson already knew in his heart how to choose; he just didn't want to say it out loud.
The more filled people's hearts are with ugliness and darkness, the more they yearn for purity. But the more they yearn for purity, the more they want to destroy it, no matter the means.
Human nature might be called "human nature" precisely because people's essence is complex enough, degenerate enough, to highlight and give the term "human nature" more meaning.