Why he gave up the punitive award is questionable based on my personal speculations of how he got "left" in solitary. My guess is, like some Lottery winners who take the quick lump-sum cash rather than the 20-year annuity, he decided that more time litigating was not for him.
Presuming the jail was accredited by BoJ (darned hard to find one that isn't, unless temporarily lost it and under some sort of court order/settlement agreement/consent decree leading to reaccredidation) there were policies and procedures by the score that had to have been violated. While the story does not directly say so, it sounds like the Sherrif and just about every deputy working in the jail somehow got out of personal liability and the County took the hit. THat means the taxpayers of the County get to pay off the guy while the Sherrif and Deputies keep their houses, cars, pensions and jobs.
stay safe.