I’ll explain like you’re 5 since you’re being childishly snarky:

If someone has a connection that can help them cover up a murder, asking, bribery, etc. isn’t going to get them to help. They would be ruined, if found out. If the person who is asking for help has dirt on the person who can help them, it’d have to be big. They can destroy their reputation, career, etc. for not helping. The person’s choice goes from being: take some money to do something that will end your career? Not worth it. To becoming: Let this person end my career, or help them & hope it doesn’t ruin my career. Choice: Being ruined. Possibly being ruined.