Is a judge held accountable for anything if he errs in his ruling, even if he believes it to be correct and it has been upheld by the Court of Cassation, while the convicted person – due to his ignorance – perceives it as unjust?

Ijtihad (independent reasoning) is susceptible to error, and a judge rules based on what he hears, not on what he knows of the unseen. That is why the Prophet, peace and blessings be upon him, said: "You people come to me with your disputes, and it may be that one of you is more eloquent in his argument than the other. So, if I rule in favor of someone a portion of his brother's right, based on what he said, then I am only cutting off for him a piece of hellfire, so he should not take it."

If a judge is qualified for the judiciary and strives to hit upon the truth, he will have two rewards if he is correct, and one reward if he errs. This is based on the Prophet's saying, peace and blessings be upon him: "If a judge rules and exerts his utmost effort (ijtihad) and is correct, he will have two rewards. And if he rules and exerts his utmost effort and errs, he will have one reward."

As for one who is not qualified to rule, it is not permissible for him to judge. If he does so, he is sinful, his ruling is not enforceable, and he has no excuse for any of that.

The reward for the erring mujtahid (one who performs ijtihad) is indicated by the Almighty's saying: {And We gave understanding of it to Solomon, and to each (of them) We gave judgment and knowledge} (21:79).