The joke above is no laughing matter. Two cars crashed, and, presumably, the lawyer saw who caused the accident. He rushes over to the scene but, rather than describe what happened, offers his services to whomever pays first. The episode draws laughs because of the attorney's unseemly disregard for conventional morality. The lawyer is not there to help; he is there to make a few bucks. The humor plays upon the anxiety we feel over the lawyer's role in administering justice. The lawyer defends whoever pays him, not whomever he believes is right. Intuitively, we feel like this moral flexibility is wrong.
Revisionists in Legal Ethics: Searching for Integrity and Legitimacy,
Yale L. & Pol'y Rev.
Available at: https://digitalcommons.law.yale.edu/ylpr/vol27/iss2/9