Compiled by Citation Safe (Digital Empire Holdings LLC) from the court’s published sanction order (decided September 30, 2026). Quotes and case details come from the order itself — check the primary source before relying on them.

Sanction teardown · E.D. New York, USA · 2026-09-30

Nantongo v. Nationwide Mortgage Bankers Inc.

What happened

In E.D. New York, USA, a filing relied on an unnamed/unconfirmed AI tool to help draft legal argument. The court identified the following problems with the citations in that filing:

Misrepresented (Case Law)

The filing cited “715 F. App’x 84” for Mpala v. Segarra, but the genuine Second Circuit decision is reported at 718 F. App’x 84. The cited reporter location corresponds to Johnson v. Turnbill, an unrelated excessive-force case. The court treated the error as an inadvertent typographical mistake and found the genuine Mpala decision readily locatable.
Misrepresented (Case Law)

The filing cited “357 F. App’x 180” for LinkCo, Inc. v. Naoyuki Akikusa, but the genuine Second Circuit decision is reported at 367 F. App’x 180. The cited reporter location corresponds to United States v. Philley, an unrelated Tenth Circuit sentencing case. The court noted that LinkCo was correctly cited in the filing’s table of authorities and treated the error as typographical.

Which AI tool

an unnamed/unconfirmed AI tool. Note: Charlotin's public database records tool attribution only where a court order, brief, or reporting on the matter states it explicitly; "unidentified" or "implied" means the record indicates AI use but does not name a specific product — we do not guess.

Outcome

Sanctions motion denied

Additional detail

Plaintiff sought sanctions against Attorney Fred Charles for citing “Mpala v. Segarra, 715 F. App’x 84” instead of the genuine “Mpala v. Segarra, 718 F. App’x 84,” and “LinkCo, Inc. v. Naoyuki Akikusa, 357 F. App’x 180” instead of “367 F. App’x 180.” The incorrect reporter numbers corresponded to unrelated cases, Johnson v. Turnbill and United States v. Philley. The court accepted Charles’s explanation that these were inadvertent typographical errors, noted that the genuine cases were readily locatable, and found no evidence of bad faith, deception, or frivolous legal argument. It denied sanctions under the court’s inherent authority, 28 U.S.C. § 1927, and Rule 11.

How Citation Safe would have caught this

Citation Safe runs three deterministic layers before a brief is filed: (1) does the citation exist against CourtListener's database of published opinions, (2) if quoted, does that exact language appear in the source, (3) does the cited case actually support the proposition it is cited for. Fabricated case citations fail Layer 1. Fabricated or misattributed quotations fail Layer 2 even when the underlying case is real. Misrepresented holdings — a real case cited for a proposition it does not support — are the target of Layer 3. None of these checks involve asking another language model whether the citation looks right; they are lookups and text-matches against the actual source, which is why a hallucinated citation has to survive a direct lookup against the authoritative source — not another model's opinion — to earn a VERIFIED stamp; our measured false-verify rate is published live at /quality.

Check a brief before you file it → · See our live false-verify rate

Source: https://www.damiencharlotin.com/documents/3181/Nantongo_v._Nationwide_USA_30_September_2026.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).