If the country does not have a good track record, it doesn't really change anything.
Based on his activity since being convicted I doubt he'll be released for significantly longer than his minimum sentence.
(If the law doesn't permit a longer minimum, then 21 years is the "maximum sentence" in that there cannot be a longer mandatory period imposed.)
I just don't see how it's fundamentally any better than the US system of minimum and maximum sentences, with some possibly some provisions for early parole reviewed every year or two after some portion "X" of the sentence has been served.
And to make it more balanced, you could also punish them for exonerating someone later found guilty (with the available evicence at the first trial re-examined).
Just rough ideas, which might not work at all, but still, as it is judges have no skin in the game (not even their reputation, sometimes it's even the inverse: some judges purposefully give harsh senteces, e.g. to blacks to score political points they'll later exploit).
I doubt that. People can be punished if they fail badly, or even die if they make a mistake in all kinds of jobs, and they still do them.
>And your second paragraph is very much in conflict with the tenet that everyone is innocent until proven guilty beyond a reasonable doubt.
Well, if there really wasn't a "reasonable doubt" (as deemed on a second look) and the first judge decided it was, then it's on them...
(Just devils' advocate, I live in a country without it or a need for it.)