This episode can be understood as a criticism of today's legal and justice systems. The parallels to the US system in particular cannot be overlooked. Unfortunately, the episode tries to raise the warning finger a little bit too often:
On the one hand, it examines the question of whether a civilized society should use the death penalty to punish crimes. According to the biblical motto "an eye for an eye". Another line of thought revolves around who should actually administer justice. Judges? Jurors? Or the victims' families? When the doctor essentially cures the felon, it raises the question of whether there are any mitigating circumstances for crimes. E.g., due to a mental or genetic illness (or even due to a problematic childhood). But the episode doesn't stop there. It also puts the finger in the wound of minorities at court. Especially here the criticism of the USA is very clear, because it is the minorities, the black community, who are punished and in prison at an above-average rate. And last but not least, the episode also wants to point out the unequal treatment of defendants. Wealthy and influential people often get away with a black eye, while the petty crook often feels the full force of the law.
All interesting questions, but too many to give them enough space in one episode.