South Korean authorities arrested Lee Jae-yong Friday, and now the de facto boss of the Samsungchaebol sits in a Seoul jail cell while prosecutors interrogate him on suspicion of bribery, embezzlement, perjury, hiding assets abroad and concealing profits gained from criminal acts. The case has raised fears that the country’s largest conglomerate will be left rudderless as the case proceeds. But if the current wave of scandals prompts corporate governance reforms, it will benefit Samsung and the South Korean economy.

Mr. Lee...