Peter L. Clinco, Deceased, C. M. Barone-Clinco, Successor in Interest, and C. M. Barone-Clinco v. Commissioner of Internal Revenue
United States Tax Court · U.S. Tax Court
Verified April 26, 2026
- Citation
- Clinco v. Commissioner, T.C. Memo. 2026-16, No. 8077-23 (T.C. Feb. 9, 2026) (Holmes, J.)
- Decided
- February 9, 2026
Summary
Petitioners' counsel Abraham R. Wagner filed briefs challenging the validity of an IRS notice of deficiency that relied on four supporting cases, three of which Judge Mark V. Holmes found did not exist as cited. "Cacchillo v. Commissioner, 130 T.C. 132 (2008)" was nonexistent (the cited page falls within Porter v. Commissioner on an unrelated section 6015(f) issue); "Miller v. Commissioner, 57 T.C. 440 (1971)" was nonexistent (the cited page falls within Winfield Manufacturing Co. v. Renegotiation Board, which makes no mention of a notice of deficiency); and "Tefel v. Commissioner, 118 T.C. 324 (2002)" was nonexistent (the cited page falls within Hillman v. Commissioner on S corporation management fees). The Commissioner flagged the citations in his answering brief, but Wagner did not clarify their origins in reply and re-listed Cacchillo in his table of authorities. The court found the "bouillabaisse of case names, reporter citations, and legal propositions suggests something cooked up by AI."
- AI tool:
- Unspecified generative AI (suspected large language model; not confirmed on the record)
What sanction did the court impose?
Judicial admonishment with no monetary sanction. The court reiterated Chief Justice Roberts's warning that briefs citing nonexistent cases are "always a bad idea" and noted that submitting fictitious caselaw is "a recipe for sanctions and a clear violation of Rule 11(b)." In a footnote, Judge Holmes wrote that "a bit of embarrassment for failure to citecheck, failure to 'fess up, and (if it occurred) use of AI to write a section of the brief is enough for now," while signaling that the Tax Court has not yet imposed formal sanctions for AI hallucinations but warning, "Tax Court has not done so. Yet." On the merits, the Commissioner prevailed on the signature challenge, gross-receipts underreporting, and the Schedule E depreciation claim; decision was entered under Rule 155.
Why does Peter L. Clinco, Deceased, C. M. Barone-Clinco, Successor in Interest, and C. M. Barone-Clinco v. Commissioner of Internal Revenue matter for law firms using AI?
Clinco is the U.S. Tax Court’s first written opinion squarely confronting AI-style hallucinated authorities, and its restraint is the point. Judge Holmes catalogued three nonexistent citations, walked through how the Commissioner had flagged them in the answering brief without correction in reply, and still elected to admonish rather than sanction, while warning that the next lawyer in this posture will not get the same forbearance. For a managing partner at a small firm with a tax practice, the takeaway is that the Tax Court is now on notice of the pattern, and that re-listing a fabricated citation in a table of authorities after opposing counsel has flagged it converts an embarrassing oversight into a Rule 11 candidate.
Sources
Further reading
Source PDF is a Westlaw printout mirrored from the Damien Charlotin hallucination database. We are working to add the underlying court docket (PACER, CourtListener, or court website) as a second source.
- The opinion does not confirm Mr. Wagner used generative AI; the court explicitly stated, "It is not absolutely clear from the record whether Mr. Wagner used generative AI to secure legal precedent for his arguments." AI use is implied from the pattern of fabrications, not established on the record.
- A non-Charlotin primary-source URL (Tax Court opinion search or aggregator mirror) was not located during verification; the Charlotin S3 mirror of the verbatim opinion is the sole cited source.