Fabricating Case Law With AI: Dismissal, Sanctions, and Professional Consequences

U.S. federal courts are handling a growing category of litigation failure: attorneys using AI to generate filings and submitting them without verification, citing cases that do not exist.

In a common law system, case law is itself part of the law. Citing a nonexistent case is not merely a research error — it is submitting fabricated legal authority to a court. That is why courts have escalated their characterization of the conduct from negligence to misrepresentation, and to bad faith.

I. No Such Case: A Court Orders Counsel to Certify "This Was an AI Hallucination"

In May 2026, in a pending copyright action in the Southern District of Florida, Judge Paul C. Huck, reviewing the plaintiff's post-trial motion, found it cited:

McGrath v. Conseco, Inc., 369 F.3d 1352 (11th Cir. 2004)

The court stated in its order that after an "extensive search" it could not locate the case.

The judge then ordered plaintiff's counsel to state whether AI had been used to draft the filing and, if no copy of the decision could be produced, to certify in writing that the citation was an "AI hallucination."

The court also found that the motion contained:

• multiple citations lacking pinpoint pages;
• citations that failed to identify the deciding court; and
• at least one case attributed to the wrong court.

The judge wrote:

"The Court relies on accurate citations to accurately and efficiently resolve disputes."

II. Blaming the Paralegal: Dismissal, Sanctions, and Lasting Professional Consequences

ByoPlanet International, LLC v. Johansson (S.D. Fla. 2025)

Beginning in March 2025, the attorney involved used AI to generate filings across eight related matters for ByoPlanet, without ever verifying the output. Hallucinated citations appeared in complaints, motions, and appellate briefs, spanning Florida federal and state courts.

On April 25, 2025, the opposing party expressly identified the hallucination problem in a motion. The attorney was formally on notice.

He then filed seven further documents containing hallucinated citations — including his response to an order to show cause. That filing, which was supposed to explain his use of AI, itself contained fabricated citations.

At the hearing, the attorney admitted using AI without verifying the output, while shifting responsibility to a paralegal, saying the documents had been drafted by an assistant and that he had not reviewed them. The court found that explanation was no mitigation at all, and expressly found bad faith.

The court ruled:

• all four federal cases dismissed, without leave to refile;
• payment of the opposing party's fees in full, totaling nearly $86,000 — the largest such sanction to date;
• for two years, every complaint filed in the Southern District of Florida must attach the sanctions order; and
• referral to The Florida Bar for disciplinary proceedings.

The practical effect of the third item: in every new matter the attorney takes in that district, the judge will see, in the first filing, the record of his sanction for fabricating AI case law. The clients permanently lost the opportunity to seek relief in those four cases.

III. Alleging a "Vast Conspiracy" by the Court: Disciplinary Referral

Whiting v. City of Athens (6th Cir. 2026)

Two Tennessee attorneys filed an appellate brief containing more than twenty false citations and factual misstatements. Their response to the show-cause order reads as a case study in what not to do:

• asserting the order was "facially invalid" and constituted "harassment" of counsel;
• alleging the court was engaged in a "vast conspiracy"; and
• contending the order was invalid because signed by the clerk rather than a judge — and twice applying to the Supreme Court for an injunction to stop the court from issuing clerk-signed orders. The Supreme Court denied both applications.

The court rejected each contention and ruled:

• $15,000 in sanctions against each attorney, $30,000 in total;
• payment of the opposing party's appellate fees and double costs; and
• referral to the chief judge for disciplinary proceedings.

The court wrote that the use of false citations went well beyond "drafting negligence" and constituted misconduct in the appellate process.

IV. Escalation: Courts Demanding Disclosure of AI Use

In April 2026, Judge Maria Valdez of the Northern District of Illinois issued an order to show cause in an intellectual property matter, requiring counsel to appear and explain why sanctions should not issue.

The trigger was two false citations in counsel's filing, plus a case that could not be found on Westlaw, Lexis, or CM/ECF.

What distinguished this order was that the disclosure demanded went beyond citation checking:

• the name of the drafter and the supervising attorney;
• whether AI was used, and which specific program;
• what steps were taken to ensure no hallucinated content appeared in the filing;
• copies of the cited cases (where they exist but were cited incorrectly); and
• the full text of the firm's internal policy on AI use, with a written copy attached.

That last item marks a shift: the court's focus has moved from specific errors in an individual case to systemic management at the firm level. Courts have begun asking whether a firm has internal controls governing AI use and verification.

V. Do Not Fail the People Who Take You Seriously

It is hard to imagine an attorney telling a client at engagement: I will use AI to generate the filings automatically, without checking them, and submit them to the court.

It is hard to imagine an attorney telling a judge at a hearing: the legal authority I submitted was fabricated with AI.

It is hard to imagine an attorney telling opposing counsel: whatever argument you raise, I will answer it with AI-generated hallucinations.

Across from every filing an attorney submits sits another group of people. They read every line, verify every case cited, and respond to every argument raised.

When all of that rests on a hallucination, what is failed is not only the court and not only the client, but everyone who took you seriously.

AI can assist litigation efficiently. It can end a legal career just as efficiently.

This article addresses general legal questions only and does not constitute legal advice on any specific matter. Outcomes depend on the specific facts, evidence, applicable law, and the court's discretion. Past results do not guarantee or predict similar outcomes in future matters.