P. M. M. c/ G. A., F. M. d. S.H.

The record

• CourtCámara de Apelación en lo Civil y Comercial, Sala II, Departamento Judicial Morón, Province of Buenos Aires
• JudgesGabriel Hernán Quadri, first vote; Laura Andrea Moro, concurring on the same grounds
• Date1 October 2026, registered as RS-722-2026
• CaseCausa MO-14691-2021, an action to collect a sum of money. The appeal was brought by the mediator against the first-instance ruling of 25 November 2025 fixing the base for the regulation of fees
• The errorA decision attributed to the Supreme Court of the Province of Buenos Aires, “Colegio de Abogados de La Plata c/ Provincia de Buenos Aires” (caso “Barrio”), 5 May 2021, cited with case number C. 121.461. The chamber found no such case under that name; the number belongs to a different case whose last movement was in 2017; the quoted summary is not in the Juba database
• ToolNot established. The chamber could not say with certainty that AI was used, but found “una fuerte probabilidad” (a strong probability) given the context
• OutcomeAppeal declared deserted under article 261 of the Civil and Commercial Procedure Code; costs to the appellant (article 68); counsel put on notice of the circumstances
• AmountNone
• The barAn official letter to the Colegio de Abogados of the department, asking it to circulate the decision and the need to verify citations. Not a disciplinary referral
• EarlierThe same chamber, Sala 1, causa MO-19435-2020 (RS 315/2025), on the same kind of error

What the court found

An appeal brief must contain a concrete and reasoned critique of the decision appealed; if it does not, the appeal is declared deserted. The chamber found that this brief was built almost entirely on citations of decisions, and that the decision carrying most of the argument could not be located:

“se cita un fallo como ‘Barrio’ que no es el clásico fallo ‘Barrios’ y que, en realidad, parecería no existir.”

Working translation: a decision is cited as “Barrio” that is not the classic “Barrios” decision and that, in reality, would appear not to exist.

The real Barrios decision, C. 124.096, concerned the supervening unconstitutionality of articles 7 and 10 of Law 23.928, and the chamber found that it does not address the point the appellant built on. The chamber noted that its Sala 1 had met the same situation in causa MO-19435-2020, “e incluso con el mismo error” (and even with the same error): a reference linked in some way to the Barrios case.

On the cause, the chamber was careful:

“no puedo afirmar, con certeza, que la cita de fallos que no existen (o al menos no están localizables) provenga de un inadecuado uso de herramientas de inteligencia artificial.”

Working translation: I cannot state with certainty that the citation of decisions that do not exist (or at least cannot be located) comes from an inappropriate use of artificial intelligence tools. But given the context and the repetition of such situations elsewhere, “existe una fuerte probabilidad de que esto es lo que haya sucedido” (there is a strong probability that this is what happened).

The chamber then explained why a false citation to a famous case worries it more than an invented one:

“Considero que este tipo de error podría ser más grave aún que la invención de un precedente dictado en un caso totalmente inexistente.”

Working translation: I consider that this type of error could be even more serious than the invention of a precedent decided in an entirely nonexistent case. A name with nothing real about it can be caught with a simple search; “La mención a un fallo conocido, en cambio, puede generar confianza inmediata en quien lo lee, que puede tender a aceptar la atribución sin cotejarla con el texto original.” (The mention of a well-known decision, by contrast, can generate immediate trust in whoever reads it, who may tend to accept the attribution without checking it against the original text.)

The chamber did not forbid the tools, “porque nada impide que lo haga” (because nothing prevents it), but told counsel that every source in a filing, not only decisions but also statutes and scholarship, must be checked to exist. Its order to the bar:

“PROCEDASE A COMUNICAR ESTA DECISIÓN, vía oficio a librarse por Secretaría, al Colegio de Abogados de este Departamento Judicial solicitando que -si lo estima pertinente y por los carriles que se consideren- se proceda a difundir entre los matriculados la importancia de verificar cuidadosamente las citas empleadas, en caso de utilizarse herramientas de inteligencia artificial generativa para preparar sus presentaciones y se destaque, especialmente, que debe ponerse especial énfasis en el control de los resultados brindados por herramientas de inteligencia artificial (incluso la ‘Visión general creada por IA’ del buscador de Google) cuando el resultado que arrojen ofrezca una referencia en la carátula del caso a algún precedente de mención o citación frecuente.”

Working translation: let this decision be communicated, by official letter issued by the Clerk’s office, to the Bar Association of this Judicial Department, asking that, if it considers it appropriate and through whatever channels it considers fit, it circulate among its members the importance of carefully verifying the citations used where generative artificial intelligence tools are used to prepare their filings, and that it stress, in particular, that special emphasis must be placed on checking the results given by artificial intelligence tools (including the “AI-created overview” of Google’s search engine) where the result they return offers, in the case name, a reference to some frequently mentioned or cited precedent.

Why it matters

Three features travel. First, the consequence fell on the case. There was no fine; the appeal was lost, with costs, because the argument rested on a decision that could not be found.

Second, the error. The chamber treated it as a famous name misused rather than a case invented from nothing, and explained why that is harder to catch: a reader recognises the name and accepts the attribution. Cervantes v. Bianco turned on the same kind of error in the Supreme Court of California.

Third, the audience. The chamber wrote to the bar of its whole judicial department, and named a search engine’s AI-created overview as a place where checking must begin.

Sources

• P. M. M. c/ G. A., F. M. d. S.H. s/ cobro ordinario de sumas de dinero, Causa MO-14691-2021, Cámara de Apelación en lo Civil y Comercial de Morón, Sala II, 1 October 2026, RS-722-2026, nine pages in Spanish, read in full for this page, from Damien Charlotin’s AI Hallucination Cases document store
• Working translation. The English on this page is Regulayer™’s rendering of the Spanish text. Where the two differ, the Spanish governs.

Related

• The full sanctions record
• Cervantes v. Bianco, a real precedent misquoted, in the Supreme Court of California
• Mata v. Avianca, the decision this chamber names as the starting point
• Brazil, CNJ Resolution 615/2025, judicial AI rules elsewhere in South America

Checked against the decision, read in full in Spanish. Working translation, not an official one. Information, not legal advice, and not advice on the law of Argentina.