After the judges of the Bet Din hear a case presented before them by two litigants, the two litigants leave before the judges discuss and deliberate. The deliberations are not held in the presence of the litigants.
Once they reach a decision, the judges call the litigants back and announce to them their decision. The Shulhan Aruch (Hoshen Mishpat, 19; listen to audio recording for precise citation) rules that it is forbidden for a judge who dissented from the majority of the Bet Din to tell the losing litigant, "I thought you were right, I was on your side, but my colleagues disagreed." A judge who tells this to a litigant, the Shulhan Aruch writes, is considered in violation of the verse, "Holech Rachil Megaleh Sod" – "One who gossips reveals secrets" (Mishleh 11:13). He sows hatred between the litigant and the other judges, and he reveals information that is meant to remain confidential. Once Bet Din reached a decision and issued its ruling, nobody should know which judges took which position. The Aruch Ha’shulhan (Rav Yechiel Michel Epstein of Nevarduk, 1829-1908) adds, "Ve’onsho Gadol Me’od" – a judge who reveals this information is deserving of very harsh punishment.
The Shulhan Aruch also writes that if one of the litigants wants a written record of the Bet Din’s ruling, the ruling is written, but the information of which judges ruled in favor of which litigant should not be disclosed. According to the ruling of the Shulhan Aruch, all the judges sign their names on the ruling – even the judge or judges who dissented from the majority ruling. This Halacha was actually the subject of a famous dispute between Maran, author of the Shulhan Aruch, and the Mabit (Rav Moshe Ben Yosef of Trani, 1505-1585), who once sat together on a Bet Din, and reached different verdicts. The majority of the judges followed Maran’s ruing, and when the court’s ruling was written down, the Mabit refused to sign the document, arguing that he was not required to sign his name on a ruling with which he did not agree. In Maran’s work of responsa, Abkat Rochel, he disputes the Mabit’s position, and asserts that all judges must sign the ruling, even those who dissented, and this is how Maran rules in the Shulhan Aruch.
A "compromise" ruling between these two views was advanced by the Radbaz (Rav David Ben Zimra, 1479-1573), who suggested that this would depend on the number of judges who presided over the case. If the omission of the dissenting judge’s signature will result in fewer than three signatures on the document, then the dissenting judge must sign his name, as having fewer than three signatures would undermine the document’s authoritativeness. But if there are three judges to sign without the dissenting judge, then according to the Radbaz, he does not have to sign. As mentioned, however, the Shulhan Aruch rules plainly that all judges must sign the ruling.
Summary: When a Bet Din issues its decision after hearing the case, nobody should be told which judges favored which side. The dissenting judge should not inform the losing litigant that he was overruled, and if the ruling is written down, then the majority decision should be written without specifying the views of individual judges, and all judges should sign the document.
