AI hallucinations in the facts section are a growing threat to litigators
By now, every litigator has heard the warnings about the costly sanctions (in multiple cases, exceeding $100,000) if a pleading contains AI-hallucinated caselaw. Most litigators using generative AI when writing their briefs are aware of the risk of fabricated case citations and the many other ways generative AI can corrupt citations to legal authorities.
What's getting far less attention is a quieter, arguably more dangerous problem: the growing prevalence of sanctions for AI-hallucinated fact cites. These are citations to the record, exhibits, depositions, emails, and any other factual discovery that either don't say what the brief claims or don't exist at all.
Both fabricated case law and fake fact cites are hard to catch on your own when a brief contains hundreds of citations, but fact cites are arguably the trickier of the two. A fabricated case at least lives somewhere checkable by anyone at the firm who has access to a legal research repository; a fake fact cite hides inside your own repository of factual evidence that is not always accessible by the people working on the document as the brief gets closer to filing.
Clearbrief is the only platform that systematically checks citations to both facts and law and displays the sources for your review as required by Rule 11 and new explicit court and bar rules in Florida, New, York, California, and many other jurisdictions.
- It flags fabricated case law automatically through our direct integration partnerships with LexisNexis and Fastcase vLex (Clio), and
- It connects every factual assertion in your brief straight to the underlying exhibit, deposition, or discovery document itself thanks to our integrations with Relativity, iManage, Netdocs, Reveal, Clio, MyCase 8AM, Sharepoint, Box, and many more.
Sanctions cases for fake or misleading citations to factual evidence are increasing
As more lawyers have started using generative AI not only for legal research drafting but for other sections of their briefs and motions, hallucinated factual evidence has made its way into more pleadings. A database that tracks AI hallucinations in court pleadings has flagged dozens of sanctions cases in 2026 where fake facts were at issue. To highlight just a few:
In a landmark "hallucinated facts" case in early 2026, the judge noted that courts across the country had largely dealt with citations to non-existent legal authority - but "this case is different, as it appears that AI was used not to hallucinate the law, but to hallucinate the facts."
- The declaration contained multiple fabricated quotations presented to the court along with manufactured citations to deposition transcripts, as if they came from sworn testimony. It also grossly mischaracterized testimony and other facts in the record. The plaintiff admitted he used generative AI to draft at least a portion of his declaration and admitted he did not review it prior to signing, despite declaring under penalty of perjury that the content was true and correct. Sanctions totaled $5,000 ($4,000 against counsel and $1,000 against the litigant) and counsel was ordered to attend a CLE course.
- In March 2026, the Court of Appeals for the 6th Circuit sanctioned a firm for fake factual citations to the Complaint and Appellees’ brief, as well as hallucinated caselaw and misrepresented quotations ($30,000, adverse costs, & potential disciplinary proceedings).
In addition to fake citations to a complaint and opposing counsel’s brief, we’ve seen:
- Experts citing nonexistent articles: In In re Soc. Media Adolescent Addiction/Pers. Inj. Prods. Liab. Litig., No. 4:22-md-03047-YGR (N.D. Cal. Feb. 17, 2026), an expert admitted academic articles in his report don't exist, attributed to an AI citation tool.
- Fabricated deposition quotes:
- In Kennon v. Ashley, No. 24-4034-JWB (D. Kan. Feb. 18, 2026), counsel quoted nine deposition passages that don't appear on the cited transcript pages. Rule 11 show-cause order.
- In Blazy v. Dep't of State, CBCA Nos. 7992, 7993 (Feb. 24, 2026), four deposition excerpts didn't appear on cited pages. Appellant admitted they were "constructed."
Check out this short clip showing how Clearbrief “hooks up” your citations to facts automatically thanks to our integrations with Relativity, iManage, Netdocs, Clio, and more.
New regulations mean that partners and anyone signing a pleading are personally responsible for verifying cited facts with their own eyes
In just the past few months, multiple jurisdictions have moved from guidance to hard rules:
- Florida's Supreme Court now requires every attorney who signs a filing to personally represent that "the legal authorities identified exist and are accurately cited"—with sanctions authorized for violations.
- New York's Part 161 codifies that anyone who uses AI in preparing a filing must independently review all cited sources and certifies, by signing, that the paper "contains no fabricated or fictitious cases, statutes, or other material."
- California's State Bar issued updated guidance making clear that "a lawyer's professional judgment cannot be delegated to AI and remains the lawyer's responsibility at all times."
- The Ninth Circuit's recent disciplinary order went further still, holding that an attorney's signature is a personal attestation that they read every cited authority with their own eyes—a duty that "cannot be delegated, disclaimed, or excused" by AI tools or subordinate drafters. The court called one attorney's admission that his team didn't "normally vet citations used by the Brief Writer" an "extraordinary confession."
Put simply: courts are done accepting "the AI got it wrong" as a defense, for facts or for law.
How Clearbrief closes the fact cite gap
Most cite-checking tools—and most habits built around them—focus on legal authority. Clearbrief was built to catch fabricated facts with the same rigor:
- Smart Linking of Fact Cites: Automatically connects and displays every factual assertion in your brief to the specific page of the underlying exhibit, deposition, or discovery document it's supposed to support. That means anyone working on the brief can easily view the source as they read the hyperlinked Word document, satisfying their ethical requirements.
- Semantic Scoring: Clearbrief's patented technology measures how closely your sentence actually maps to the language on the cited page, flagging anything with a middling or low score before a judge ever sees it. It doesn't just tell you a citation exists; it tells you whether it says what you claim it says.
- Globally Add Fact Cites, now filterable by document type: If you drafted a facts section with an LLM and need pincites added to the factual evidence, you can select that entire section of text and Clearbrief will suggest and insert a citation after each sentence. You can also choose exactly which file types to pull suggestions from—say, emails and exhibits, but not a party's own brief.
- Build a Cite-check Report for an audit trail: When you run Clearbrief’s Analyzer, you can document you did it with a Cite-Check Report that can be shared with any other attorneys signing the brief.
- Opposing-brief analysis: Convert a PDF from opposing counsel into an analyzable Word document and run the same fact- and case-verification diagnostic on their filing that you'd run on your own—closing the "we didn't catch it either" exposure courts are now penalizing.
And because Clearbrief's Analyzer runs on deterministic technology rather than generative AI, it cannot itself hallucinate a red flag—it can only tell you, accurately, what is and isn't supported by evidence.
Common mistakes that let fake fact cites through
Treating fact-checking as less important once the caselaw looks clean. A brief with airtight legal authority and fabricated facts is just as vulnerable to sanctions—arguably more so, since fact fabrication often reads as closer to intentional misrepresentation than a formatting error.
Assuming “the junior attorneys will check the facts.” Often, only the junior lawyers on the team know how to access and pull up the underlying factual evidence from repositories like Relativity. Without a systematic way to let others on the team quickly double check work product before filing, any facts section is at risk of containing mistakes that the court will sanction you and your clients for.
Skipping verifying the factual evidence when time is short. Courts have made clear that time pressure isn't a defense. The Ninth Circuit's order singled out exactly this excuse in referring an attorney for discipline.
Not checking opposing counsel’s filings with the same scrutiny. As the recent wave of shared-sanction cases shows, "we didn't write it" is no longer a shield against "we didn't catch it."
Conclusion: Fact cites can make or break your case as well as your reputation. Check them systematically.
The rules have caught up to the risk. Florida, New York, California, and the Ninth Circuit have all made clear in the past few months that signing a filing means personally standing behind every cited source, not just cited cases.
The fix is an operations matter. Litigation teams need to build a fact-cite verification step into the firm’s filing workflow the same way you've already built in case-law verification. Tools like Clearbrief that connect every factual assertion directly to its underlying source, score how well it actually holds up, and generate an audit trail as you go turn that requirement from a burden into a quick process before you hit file.
Want to learn more about putting a cite-checking Ops policy in place? Email us at hello@clearbrief to get a full demo of Clearbrief, and check out our CEO’s blog post on how to create a operations policy on checking both facts and law with Clearbrief.
