I think it's a blindspot arising out of the independent historical development of equitable compensation for wrongdoing and the expansion and then much later slow retraction of sovereign immunity. By all logic under civil law you ought to have a financial remedy because civil law isn't about punishing anyone or even really assigning blame in any moral sense, but resetting positions to before the harm. But the vast majority of that historical legal development happened during a period of common law legal history where sovereign immunity was absolute. Even now it's still doctrinally absolute in most common law countries, it's just that legislative supremacy or constitutional developments post-enlightenment and age of revolutions allow sovereigns or constitutional equivalents to shed some of that immunity on a voluntary basis. And by the time "sovereigns" began divesting their immunity in limited circumstances around the 1940s-60s throughout the common law world, we were long past the medieval-1700s practices that actually do have some limited precedent for suing jailors and constables for material losses while imprisoned or detained.