Friend v. Serpa
Florida Fourth District Court of Appeal · Fla. 4th DCA · Florida bar guidance
Conduct
Pro se appellee cited multiple nonexistent cases in a Florida appellate brief; court characterized these as 'phantom authority.'
Consequence
Nonexistent authorities expressly disregarded; no sanctions imposed; warning about Fla. R. App. P. 9.410(a) authority issued.
Lesson
Friend v. Serpa is the Fla. 4th DCA's anchor AI-citation authority; subsequent 4th DCA orders cite it to position the phantom-authority warning.
Verified May 14, 2026
- Citation
- Friend v. Serpa, 425 So. 3d 51 (Fla. 4th DCA 2025) (per curiam); also at 2025 WL 3648538 (Fla. 4th DCA Dec. 17, 2025)
- Decided
- December 17, 2025
Summary
Pro se appellee Carlos Serpa Jr. cited multiple cases that do not exist in his brief before the Florida Fourth District Court of Appeal, in a family-law appeal from the Circuit Court for the Fifteenth Judicial Circuit, Palm Beach County (L.T. Case No. 50-2022-DR-000981-XXXX-MB, Judge Karen M. Miller). In a per curiam opinion, the panel (Kuntz, C.J., Ciklin and Shaw, JJ.) expressly disregarded the nonexistent "phantom authority" and cautioned that the court has authority to sanction under Florida Rule of Appellate Procedure 9.410(a) for failure to comply with Florida Rule of Appellate Procedure 9.210(c), which requires that cited authority support the stated proposition. No sanctions were imposed. The opinion is subsequently cited in Francois v. Vive Financial (Mar. 18, 2026) and Roussell v. Bank of New York Mellon (Mar. 11, 2026) as the Fourth District's anchor AI-citation authority.
- AI tool:
- Generative AI (court addressed use of 'artificial intelligence' explicitly; specific tool not named)
What sanction did the court impose?
Affirmed on the merits. Nonexistent "phantom authority" expressly disregarded. No sanctions imposed but explicit warning that the court has authority to sanction under Fla. R. App. P. 9.410(a) for violation of Rule 9.210(c). Cites Goya v. Hayashida, 418 So. 3d 652, 656 (Fla. 4th DCA 2025), as the prior Fla. 4th DCA precedent imposing sanctions for fictitious case law.
Why does Friend v. Serpa matter for law firms using AI?
Friend v. Serpa is the Fourth District Court of Appeal’s anchor AI-citation warning opinion, the decision that subsequent 2026 Fourth District orders cite when positioning the phantom-authority rule. The per curiam opinion is brief, but its language is precise: “Those who use artificial intelligence to assist in these submissions must ensure their accuracy.” That framing places the verification duty on the human author, not the AI tool, and applies it to pro se litigants and attorneys alike.
The procedural posture is unusual in the AI-citation corpus: the misconduct was by the appellee (Carlos Serpa), not the appellant. Serpa prevailed on the merits (the appeal was affirmed), but the court nonetheless flagged his phantom citations in writing. For firms tracking AI-citation exposure, this matters because it confirms courts will address fabricated authority regardless of outcome on the merits, and regardless of which side filed the defective brief.
The Fourth District did not impose sanctions here, but its citation to Goya v. Hayashida, 418 So. 3d 652, 656 (Fla. 4th DCA 2025), signals that the machinery exists. Goya imposed sanctions on a pro se litigant for fictitious case law; Friend positions that precedent as the backstop for future Fourth District enforcement. Francois v. Vive Financial (March 18, 2026) and Roussell v. Bank of New York Mellon (March 11, 2026) both quote Friend’s AI-responsibility language verbatim and issue warnings under Fla. R. App. P. 9.410(a). The pattern tracks what O’Brien v. Flick did in the Southern District of Florida: one published opinion becomes the first-citation anchor for a cluster of subsequent orders.
Implications for your firm
Operational steps a firm reading this case may wish to consider documenting. Strategic and rule-application calls belong to your firm's attorneys.
- Track Friend v. Serpa (425 So. 3d 51) as the Fla. 4th DCA's collecting-cases anchor: it is cited in Francois (Mar. 2026) and Roussell (Mar. 2026) for the proposition that both attorneys and pro se litigants 'are responsible for the content of their submissions to the court' and must ensure AI-assisted submissions are accurate.
- Fla. R. App. P. 9.210(c) requires that citations support the stated proposition; Friend positions future violations as Rule 9.410(a) sanctionable conduct. When opposing a pro se party in the Fourth District who cites questionable authority, cite Friend and Rule 9.210(c) compliance in any sanctions motion.
- Note the appellee posture: the AI-citation misconduct here was on the winning side (appellee prevailed on affirmance); that eliminates any argument that phantom citations are only a risk when the filer loses. Courts flag phantom authority regardless of outcome on the merits.