Legal teams at law firms advising on cross-border merger transactions touching the 2025 OECD Merger Review Recommendation are increasingly using AI to draft client memos on the Recommendation's operative architecture, generate partner-level briefings on the remedies hierarchy and failing firm defence, and validate Section-level citation language in regulatory submissions, transactional documents, and authority-engagement papers.
The RLB Specialist Panel put a set of practitioner-grade questions on the 2025 OECD Merger Review Recommendation to two frontier AI models with web search active. Each question is prepared by the Panel based on the workflows that legal teams at law firms actually use AI for under the OECD's 2025 revision of the Recommendation of the Council on Merger Review (OECD/LEGAL/0333). The Panel then binds every AI response to verbatim regulator-issued source text held as primary substrate.
On the 2025 OECD Merger Review Recommendation, the AI subjects returned five hallucinated answers for legal teams at law firms, in the form of Structure Inflation, Misattributed Cross-Jurisdictional Doctrine, Open-Interval Collapse, and Inter-Alia-to-Closed-Test Conversion.
For legal teams at law firms advising on cross-border merger transactions touching the 2025 OECD Merger Review Recommendation, citation accuracy on the operative architecture, on Section IV.3 remedies hierarchy, and on Section III.11.b failing firm defence is load-bearing in every authority-facing submission, every board memo, and every transactional document. A counterparty or competition authority who identifies a structural inflation, a misattributed sub-hierarchy, or a closed-cumulative-test framing on first reading calls the entire piece of advice into question.
The structural-architecture failure is the most directly visible: a board memo or regulator-facing submission that lists 'international co-operation' or 'monitoring' as operative RECOMMENDS sections is wrong on first reading. The Section IV.3 EU sub-hierarchy import is the most insidious failure, reading as authoritative because the EU framework is real, but presenting EU practice as OECD content imports the wrong normative baseline into the firm's remedy strategy.
The published Specialist Panel findings carry the following citation identifiers:
RLB-H-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q001-Opus47 (Invented operative sections; ex-post assessment omitted)RLB-H-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q001-Sonnet46 (Invented operative sections; ex-post assessment omitted)RLB-H-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q002-Sonnet46 (EU fix-it-first hierarchy cited as OECD text)RLB-H-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q004-Sonnet46 (Two-tier reporting cycle collapsed to uniform five-year interval)RLB-H-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q005-Opus47 (Failing firm defence conditions presented as closed exhaustive test)RLB-H-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q005-Sonnet46 (Failing firm defence conditions presented as closed exhaustive test)RLB-H-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q006-Opus47 (Transnational co-operation invented as operative section; Section V dropped)This is the consolidated view of findings. Click the Citation IDs or 'see details →' on any item for the full details for each finding.
A merger control matrix or jurisdictional coverage memo drafted using AI's characterisation of OECD/LEGAL/0333 will describe the wrong operative architecture to the client, listing a co-operation obligation that does not exist as a standalone section and omitting the ex-post assessment provision that directly affects how a jurisdiction's review framework will evolve post-clearance.
For the law firm, this error in a client opinion or regulatory briefing is a textbook professional indemnity exposure: the firm has delivered materially wrong information about the content of a benchmark instrument that the client is relying on to frame their multi-jurisdictional merger strategy. The OECD's Competition Committee has no direct enforcement power, but an error here flows into advice on national implementations, where the consequences can include a jurisdictional gap in notification coverage or a missed obligation in a jurisdiction following the Recommendation closely.
AI presented the EU Merger Regulation's fix-it-first, upfront-buyer, crown-jewel hierarchy as the operative content of OECD/LEGAL/0333 Section IV.3, supported by real OECD citations that do not actually contain this hierarchy, meaning a reviewer relying on the cited sources without reading them would not catch the error.
For a law firm advising a client on remedy design in an OECD Adherent jurisdiction outside the EU, this produces advice calibrated to the wrong benchmark standard. If the client structures a remedy package on the assumption that the OECD framework requires the EU-style fix-it-first priority ordering, and the relevant authority does not apply that hierarchy, the firm has given substantively wrong strategic advice. The PI exposure is direct, and the misattributed citations make it worse: the error would pass a superficial document-review check.
AI stated that Section VIII.c requires the Competition Committee to report every five years on a uniform recurring cycle, projecting 2030 and 2035 as the first two report dates. The actual provision establishes a two-tier structure: an initial report within five years (by 2030), then reports at least every ten years thereafter, meaning the second report falls due by 2040, not 2035.
Any regulatory implementation timeline, compliance calendar, or policy-watch memorandum built on the AI's characterisation will misstate when the next review of the Recommendation's continued relevance is expected. For a client tracking the likelihood of further revision to their operating jurisdictions' merger control regimes, this is a materially wrong deliverable, a wrong-deliverable failure that would not survive comparison against the primary text but that could travel undetected through an AI-assisted drafting process.
AI presented the failing firm defence under Section III.11.b as a closed cumulative test with three exhaustive conditions, dropping the 'inter alia' qualifier that signals a non-exhaustive standard. Two separate AI tools produced this same closed framing, and both cited real OECD sources that do not support the closed-test characterisation.
For a law firm advising a client on whether a failing firm defence is available, the difference is material: a closed three-condition test tells the client the defence succeeds or fails on those three elements alone, while the 'inter alia' standard warns that the authority may demand additional evidence beyond those elements. Advice built on the AI's version understates the evidentiary risk, exposes the client to a failed defence on a basis the firm did not flag, and creates a direct professional indemnity claim.
The pretextual citations compound this: they give the appearance of primary-source support for an answer that misrepresents the operative text.
AI described 'Transnational Co-operation' as a standalone fifth operative RECOMMENDS section of OECD/LEGAL/0333 and omitted Section V (ex-post assessment) as a named operative provision, producing a fundamentally wrong characterisation of the Recommendation's operative scope that mirrors the error in Finding 1 but was generated independently.
The convergent nature of this failure across multiple AI tools is the significant signal: it is not a random confabulation but a systematic misrepresentation of this instrument's structure. Any law firm that allows AI-assisted research on this Recommendation into client-facing work without primary-source verification of the operative section list is systematically exposed to producing wrong regulatory characterisations across its merger control practice, with PI consequences that scale with the number of matters on which the error propagates.
Every finding on this page compares an AI subject's account of the rule against the regulator's verbatim text from the regulator's own portal. Both are linked. Each delta, its root causes, and impact analysis are documented and published with immutable Citation IDs.