Gemara

3a - Question: If commoners may judge, they should be exempt if they err!

Answer: All the more so, this would discourage loans!

5a: Once, Mar Zutra brei d'Rav Nachman judged a case and erred. Rav Yosef said that he is exempt only if the parties accepted him for a judge.

(Rav and Shmuel): If someone wants to judge and be exempt if he errs, he should ask permission from the Reish Galusa.

(Mishnah #1): A monetary verdict can be overturned, whether Zechus or Chiyuv:

Contradiction (Mishnah #2): If a judge acquitted the guilty or obligated the innocent, what he did stands. He pays for the loss that he caused.

Answer #1 (Rav Yosef): Mishnah #1 refers to a Mumcheh (expert). Mishnah #2 discusses an amateur.

Question: We do not overturn the verdict of a Mumcheh!

(Mishnah): A Mumcheh l'Rabim is exempt (if he erred. If he can overturn his verdict, there is nothing to pay for!)

Answer #1 (Rav Nachman): A bigger Chacham can overturn the verdict. If there is no bigger Chacham, the verdict stands.

Answer #2 (Rav Sheshes): If he was To'eh bi'Dvar Mishnah (made a clearcut mistake), we overturn the verdict. If he was To'eh b'Shikul ha'Da'as (ruled unlike the primary opinion), the verdict stands.

Answer #2 (to the Contradiction - Rav Chisda): If the judge himself transferred the money, the verdict stands. If he did not, we overturn the verdict.

(Ravina): He acquitted the guilty, i.e. a lender had a security, and the judge exempted the borrower, took the security and returned it to him.

Question: Regarding 'he acquitted the guilty' he said 'you are exempt.' He did not transfer money!

Answer (Ravina): Almoni had a security of Ploni. When the judge exempted Ploni, he took the security and gave it to Ploni.

Bechoros 28b (Mishnah): If a judge acquitted the guilty or obligated the innocent, or was Metamei (declared to be Tamei) what is Tahor or was Metaher what is Tamei, the verdict stands, and he pays for the loss he caused.

A Mumcheh (expert) authorized by Beis Din is exempt.

Suggestion: Our Stam (unauthored) Mishnah is like R. Meir, who obligates for Garmi (causing damage).

Rejection (R. Ilai): It is like everyone. The case is, the judge himself executed his ruling and transferred the money from one party to the other.

Rishonim

Rif: A mistaken ruling stands if the judge himself transferred the money, like Rav Chisda said. Also in Bechoros we established the Mishnah like this. The Halachah follows Rav Sheshes, who say that we retract from a To'eh bi'Dvar Mishnah. If an unqualified judge erred and did not transfer the money himself, if the party that deserves it can retrieve it from the other party, he does. If he cannot, the judge must pay, for he caused a loss. We obligate for Garmi.

Rebuttal (Ba'al ha'Ma'or 10b): Since we obligate for Garmi like R. Meir, we do not establish the Mishnah to be when the judge himself transferred the money. We do not hold like R. Ila'a and Rav Chisda, rather, like Rav Yosef, Rav Nachman and Rav Sheshes. Rav Yosef, Rav Nachman and Rav Sheshes do not argue; they give different answers. The Halachah follows Rav Nachman in monetary laws.

Defense (Milchamos Hash-m): The Halachah follows Rav Chisda, for Ravina, who is Basra, answered for him. Rav Chisda explains the Mishnah like R. Meir. If he held like R. Ila'a, the Gemara would have said so! Rather, Rav Chisda teaches that the Halachah is that the verdict is reversed. Even if usually one cannot do so, since this is the Halachah, we cannot obligate a judge due to Garmi even when the party cannot get back his money, for there was no sure loss. A judge is no worse than a Moser (one who incites the kingdom to take others' property). A Moser must pay only if he himself gave over the property! The Ba'al ha'Ma'or says that we retract To'eh bi'Dvar Mishnah, for it was a total mistake and one may not rely on it at all. This is wrong. Not all know every Sifra, Sifri, Tosefta and Gemara. Even a mistake about Amora'im's teachings is To'eh bi'Dvar Mishnah!

Rosh (Sanhedrin 4:5, according to the Rif): We resolve the Mishnayos like Rav Chisda said. The judged erred in Shikul ha'Da'as. The verdict is reversed only if he did not hand over the money. When the judge is exempt, we reverse the verdict lest the party lose money.

Rebuttal (Rosh): The Mishnah in Bechoros exempts a Mumcheh. This refers to the Reisha, which obligates an amateur because the law is not reversed! Even so, a Mumcheh is exempt! Also, why did Rav Chisda need to say that he is liable when he transferred the money himself? He could have said that an amateur is liable! Also, we do not exempt a judge for mistakes, lest this deter people from lending. If the verdict is reversed, people would not be deterred even if the judge is exempt! Also, the Rif was forced to say that the verdict stands when the people did not accept the judge. The opposite is more reasonable! Also, a judge who asks permission from the Reish Galusa is exempt. This implies that his verdict stands, yet permission exempts! The Halachah is unlike Rav Chisda, for he explains like Chachamim, but the Halachah follows R. Meir.

Nimukei Yosef (11a): Since the Torah obligates a Mumcheh to judge, he is exempt if he erred, just like we say that if Chachamim enacted that commoners may judge, they should be exempt if they err, for the Torah authorizes them. Their mistake is like Ones.

Rambam (Hilchos Sanhedrin 6:2): An error in Shikul ha'Da'as is when two Tana'im or Amora'im argue with each other, and the Halachah was not explicitly fixed like either one, and the judge ruled like one, unaware that everyone follows the other. If a Mumcheh made such an error and he had permission from the Reish Galusa, or he had no permission but the parties accepted him on themselves, since he is a Mumcheh, the verdict is reversed. If it cannot be reversed, the judge is exempt.

Rambam (3): If the judge was a Mumcheh but did not have permission from the Reish Galusa or the parties, or he was an amateur but the parties accepted him on themselves to judge properly, and he erred about b'Shikul ha'Da'as, if he transferred the money, what he did stands, and he must pay from his money. If he did not transfer the money, the verdict is reversed. If it cannot be reversed, he pays from his money.

Mordechai (676-677): Maharam said that even nowadays judges are liable. Even if you will say that nowadays that we force judges to judge they are exempt, for they have no choice, in any case they must retract if they erred. If they do not want to retract, it is proper that they pay!

Poskim

Shulchan Aruch (CM 25:2): If a judge erred about b'Shikul ha'Da'as, e.g. two Tana'im or Amora'im argue, and the Halachah was not explicitly fixed like either one, and the judge ruled like one, unaware that everyone follows the other: if the judge was a Mumcheh with permission from the Reish Galusa, or had no permission but the parties accepted him on themselves, since he is a Mumcheh, the the verdict is reversed. If it cannot be reversed, the judge is exempt.

Rema: Three commoners are like one expert.

SMA (15): This teaches that if the parties accepted them upon themselves, the judges are exempt.

Shulchan Aruch (3): If the judge was a Mumcheh but he did not have permission from the Reish Galusa or the parties, or he was an amateur but the parties accepted him on themselves to judge properly, and he erred about b'Shikul ha'Da'as, if he transferred the money, what he did stands, and he must pay from his money. If he did not transfer the money, the verdict is reversed. If it cannot be reversed, he pays from his money.

Rema: Some say that even if he did not transfer the money, the verdict stands and he pays. However, if the parties accepted upon themselves Din or error, or nowadays that the Tzibur forces judges to judge against their will, they are exempt even for mistakes, for what can they do? In any case they must retract if they erred, and if they do not want to retract, they must pay.

Shach (31): The Rosh, Tur and other Poskim say Stam, that he is liable, and they were in the era of the Mordechai, and some were after him! Also the Mordechai was not certain. He merely said 'even if you will say that nowadays they are exempt, they must retract.' Sefer ha'Chachmah says that even nowadays they are liable, but some exempt. The Rema should have said some say that nowadays they are exempt.

Gra (30,31): If commoners may judge, they are like experts, so they should be exempt (3a)! An expert is exempt, for what else can he do?