This is correct. I know the tendency on the left lately (and especially on Lemmy) is that the ends always justify the means, but the rule of law is more important. Rights of the accused are crucial to maintaining democracy. If the state fucks up its case or breaks the rules, they need to be held to account even if it means pieces of shit sometimes get away with things. Reference the entire Miranda case the warnings are based on, for example.
I also believe karma is a bitch. OJ got off but he was held civilly liable and he went on to commit other crimes that eventually landed him in prison for a significant chunk of his life. (To that point, karma eventually caught up with Miranda also…)