From Presumed Neutrality to Designed Neutrality: Court-Appointed Medical Experts, Bias, and Malpractice Litigation in Brazil

Resumo

Medical-malpractice adjudication depends heavily on expert evidence because courts must reconstruct conduct, causation, and damage from facts beyond lay understanding. Brazil's civil-law model relies usually on a single court-appointed expert supported by party-appointed technical assistants, an approach prized for neutrality, procedural economy, and judicial control. Yet in malpractice cases, this structure can concentrate decisive authority in one physician whose subspecialty competence, methodology, and independence often go untested. This article examines whether Brazil's single-expert model delivers genuine epistemic neutrality or merely presumes formal impartiality. Rather than a systematic review, it offers doctrinal and comparative legal analysis grounded in empirical and theoretical literature on expert evidence and forensic bias. Brazilian procedural law sets a rigorous standard: Article 473 of the Code of Civil Procedure requires experts to define the examination's subject matter, disclose their technical-scientific method, confirm the method's general acceptance, and answer all posed questions conclusively. In practice, however, empirical studies document frequent non-compliance: experts often stray from the court-defined scope, omit methodological disclosure, skip evidence-based citations, or produce non-auditable reports. These failures intensify when generalist physicians assess conduct in demanding subspecialties like neuro or plastic surgery. The article argues that Brazilian malpractice adjudication must shift from presumed to designed neutrality, built through subspecialty-matched experts, structured conflict-of-interest disclosure, auditable reasoning chains, ex ante standard-of-care benchmarks, and substantive judicial review of report reliability. Enforced properly, Article 473's principles curb analytic bias by making reasoning transparent and contestable. They cannot, however, reach the deeper ecology of bias (cognitive, contextual, professional, economic, institutional, and metacognitive) that shapes opinions before they reach the legal report. Expert neutrality, the article concludes, is not a status automatically conferred by appointment but an institutional outcome requiring documentation, testing, and justification before judgment.