What do the primary operative sections of the 2025 OECD Merger Review Recommendation (OECD/LEGAL/0333) address, and what topics were deliberately separated into other OECD instruments rather than included in this Recommendation?
On a second, differently-framed question about the same instrument, the model again generated a six-section structure and this time fabricated a specific cross-reference, attributing broader cooperation governance to OECD/LEGAL/0408 (2014), a legal instrument identifier that does not appear in the 2025 Recommendation's text. The response constructed a coherent-sounding inter-instrument division of scope that is consistent with how OECD governance generally works but is not what the 2025 Recommendation states. The repeated structural fabrication across independently posed questions, with web search active, confirms the reconstruction is drawn from training rather than corrected by retrieval.
The fabrication of a specific OECD legal instrument identifier (OECD/LEGAL/0408 [2014]) as the basis for a cross-instrument scope division is a citation-generation failure: the model produced a correctly-formatted OECD legal reference that either does not exist or is misattributed. With web search active, the retrieval layer did not flag the fabrication — the generated citation passed the model's internal plausibility check without verification against a retrieved source. This implicates the citation-generation and citation-verification subsystems.
Replicating the pattern seen in Finding 1, AI tools described a 'Transnational Co-operation' section as an operative RECOMMENDS block of the Recommendation and omitted Section V (ex-post assessment) as a standalone obligation. A practitioner relying on this output to map the Recommendation's operative obligations for a client across multiple OECD-adherent jurisdictions will produce a structurally incorrect compliance map, one that invents an obligation that does not appear as a discrete RECOMMENDS section and omits one that does.
Each finding has a stable Citation ID (RLB-F-… for aggregated case-study findings, RLB-H-… for raw per-model hallucinations) — like a DOI, the ID always resolves to the canonical finding even if URLs change.
RegLeg Specialist Panel, Finding#5, Co-operation section invented; ex-post section omitted [RLB-F-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q006], RegLegBrief AI Hallucination Research (June 11, 2026), https://reglegbrief.com/regulators/j1/int/OECD/OECD-MERGER-REVIEW-RECOMMENDATION-2025/practitioners/lawyers/finding/INT-OECD-INT-001-OECD-MERGER-REVIEW-RECOMMENDATION-2025-v1-006/.
RegLeg Specialist Panel (2026). "Finding#5, Co-operation section invented; ex-post section omitted — Practitioners — Lawyers." Citation ID: RLB-F-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q006. RegLegBrief AI Hallucination Research, published 2026-06-11. https://reglegbrief.com/regulators/j1/int/OECD/OECD-MERGER-REVIEW-RECOMMENDATION-2025/practitioners/lawyers/finding/INT-OECD-INT-001-OECD-MERGER-REVIEW-RECOMMENDATION-2025-v1-006/
RegLeg Specialist Panel. (2026). Finding#5, Co-operation section invented; ex-post section omitted [Hallucination finding RLB-F-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q006]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j1/int/OECD/OECD-MERGER-REVIEW-RECOMMENDATION-2025/practitioners/lawyers/finding/INT-OECD-INT-001-OECD-MERGER-REVIEW-RECOMMENDATION-2025-v1-006/
@misc{reglegbrief_RLB_F_INT_OECD_OECD_MERGER_REVIEW_RECOMMENDATION_2025_Q006,
author = {RegLeg Specialist Panel},
title = {Finding#5, Co-operation section invented; ex-post section omitted},
year = {2026},
publisher = {RegLegBrief AI Hallucination Research},
note = {Hallucination finding Citation ID: RLB-F-INT-OECD-OECD-MERGER-REVIEW-RECOMMENDATION-2025-Q006},
url = {https://reglegbrief.com/regulators/j1/int/OECD/OECD-MERGER-REVIEW-RECOMMENDATION-2025/practitioners/lawyers/finding/INT-OECD-INT-001-OECD-MERGER-REVIEW-RECOMMENDATION-2025-v1-006/}
}
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.