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Incident Tracker / United States (state)

Leiske v. Kidd, C.A. No. 2025-0426-CDW (LWW) (Del. Ch.)

·Court of Chancery of Delaware·US-STATEOther

In the Delaware Court of Chancery, plaintiffs' counsel filed an answering brief with fictitious citations, fabricated quotations and hallucinated propositions from a generative-AI tool, then only stripped quotation marks when 'correcting' it. Vice Chancellor Lori W. Will issued a Rule 11(c) rule to show cause against signatory Richard P. Rollo and his firm Richards, Layton & Finger; sanctions are pending.

Court
Court of Chancery of Delaware
Date
2026-07-01
Who used the AI
Not recorded
AI tool
Not identified in the record
Conduct
In an advancement dispute, plaintiffs' counsel's answering brief (filed 22 Jan 2026) contained fictitious citations, fabricated quotations and hallucinated legal propositions produced by an unspecified generative-AI ('GenAI') tool used to revise the brief. Counsel admitted failing to verify the citations, attributing the oversight to a paralegal's review; the 'corrected' brief merely removed quotation marks without fixing the false descriptions, and counsel faulted opposing counsel for raising the errors without a meet-and-confer.
Outcome
Other
Penalty
No monetary penalty recorded
Regulatory outcome
No separate regulatory disposition recorded
Status
Verified against listed sources
Last checked
2026-09-16

What was fabricated or misused

  • Fictitious citations, fabricated quotations, and hallucinated legal propositions in the January 22, 2026 Answering Brief; the letter opinion did not reproduce all citations.
  • Perconti v. Thornton Oil Corp., 2002 WL 982419 (Del. Ch. May 3, 2002) — cited for a fiduciary-stakes proposition the court said is absent from Perconti

What the court said

“On January 27, the defendants’ reply brief identified that the Answering Brief contained fictitious citations, fabricated quotations, and hallucinated legal propositions.”
Court of Chancery of Delaware, p. 1
“Counsel admitted failing to verify the accuracy of the citations before filing, attributing the oversight to a paralegal’s review.”
Court of Chancery of Delaware, p. 2
“A fictitious citation is not “existing law.””
Court of Chancery of Delaware, p. 5
“There is nothing to negotiate or compromise when an attorney submits false citations to a tribunal, and opposing counsel is justified in bringing such misrepresentations directly to the court’s attention.”
Court of Chancery of Delaware, p. 6

Timeline

  1. Plaintiffs filed the Answering Brief opposing exceptions.
  2. Defendants identified fictitious citations and hallucinated propositions.
  3. Plaintiffs' counsel acknowledged GenAI use and filed a corrected brief.
  4. Counsel faulted defendants for raising the errors without meeting and conferring.
  5. Court retained jurisdiction over any remedy for GenAI errors.
  6. Vice Chancellor Will issued the Rule 11 show-cause order.
  7. Deadline set for lawyer and firm affidavits on sanctions.

Why this case matters

Leiske is a Delaware Chancery example where the AI issue moved beyond a single bad brief to firm governance. Vice Chancellor Will ordered both the signatory lawyer and Richards, Layton & Finger to answer because Rule 11(c)(1) can make a firm jointly responsible for a partner's filing. That distinguishes it from Dineen/Shibata, where sanctions were against a self-represented party, and from Northbound, where the remedy was a regulator referral.

Practice note

Any firm permitting GenAI drafting should require a written cite-check before filing, done against Westlaw, LexisNexis or an official source and reviewed by an attorney. A paralegal check is not enough to discharge Rule 11. If a corrected brief is needed, re-read the underlying cases and fix the proposition, not merely the quotation marks.

Primary sources for this incident

Related regulation records for this incident

No related regulation record has been linked to this incident yet.

Similar incidents on the record

Cite this record

SafeLegalAI Global Legal AI Incident Tracker, “Leiske v. Kidd, C.A. No. 2025-0426-CDW (LWW) (Del. Ch.)”, safelegalai.com/tracker/leiske-v-kidd (accessed 2026-09-16). Data: CC BY 4.0.

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