AI-Fabricated Case Law and the Ethical Standards of the Brazilian Bar Association

This paper critically analyzes the ethical and legal responsibility of the legal profession in the face of the "hallucination" phenomenon in generative Artificial Intelligence systems, specifically regarding the creation of non-existent case law in procedural documents. Based on a legal-dogmatic study and analysis of paradigmatic cases in Brazilian and North American courts occurring between 2024 and 2025, the research demonstrates how the absence of specialized human review (AI complacency) violates core provisions of the Brazilian Bar Association (OAB) Statute and Code of Ethics, such as the duties of veracity, good faith, and professional diligence. Finally, the work proposes practical guidelines for prompt engineering and technical supervision to mitigate algorithmic risks and preserve the integrity of the administration of justice.