Process is a vital element of the law. If we can’t even get our shit together to properly prosecute someone, then they don’t get punished for their crime. Frankly, with the sheer amount of unethical behavior by judges, this should happen far more often. You’ll very quickly see improvements in the justice when the actual consequences are fucking rapists and murderers go free.
But either way, this is arguably one of the best parts of American law: a way for the system to hold itself accountable. The consequence for this level of due process violation, as we can clearly see, can be severe.
And yes, I get that the guy was convicted, I agree he did it. But he received this sentence and it would be a miscarriage of justice to later give him a harsher sentence just because of a process failure. Also, for what it’s worth, prison in America is of limited benefit. It can keep some truly dangerous people away from the general population, but otherwise is a great place for low-mid level criminals to become better and more dangerous criminals. This guy would be out in four years and, most likely, have become better at both violent crime and not getting caught all because of prison.