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AI Labs · updated 2026-05-26 · methodology v2.1

Finding on 'Q020 Probe' for Claude Sonnet 4.6 with web search ON

RLB Citation ID: RLB-H-GB-FCA-CONSUMER-DUTY-PS22-9-Q020-Sonnet46
What the RLB Specialist Panel found

Finding on 'Q020 Probe' for Claude Sonnet 4.6 with web search ON

  • Question (paraphrased to protect IP): Which FCA Dear CEO letters remain in force after Consumer Duty implementation, and how many pre-Consumer Duty letters did the FCA formally withdraw?
  • AI's response: > "there is no publicly available consolidated list in the search results specifying exactly which pre-Consumer Duty letters have been formally withdrawn and how many remain in force as at 2025... I cannot provide a verified count or a complete current list from the available search results."
  • Regulator's text: From FS25/2 (March 2025): FCA reviewed all Dear CEO letters pre-dating the 2022-25 strategy and withdrew 90+ such letters. These are no longer live supervisory expectations.
  • Why the AI went wrong: The model again declined to answer a question for which a published FCA document (FS25/2, March 2025) provides a direct and specific answer. The model's stated inability to find a verified count contrasts with the FCA's published record. Additionally, one of the cited sources in the model's response was assessed as fabricated — a URL that does not correspond to a real Clifford Chance publication on this topic. The combination of an evasion response on verifiable content and a fabricated citation is the most concerning failure pattern in this evaluation.
  • Cited source(s):
  • https://www.fca.org.uk/news/news-stories/next-steps-consumer-duty-rule-review — Pretextual
  • https://www.cliffordchance.com/insights/resources/blogs/regulatory-investigat... — Fabricated
  • Regulator portal (if any cited link is dud): https://www.fca.org.uk
Impact for this audience

This finding combines two failure modes: an evasion response on verifiable content, and a fabricated citation. The fabricated Clifford Chance URL is the only explicitly fabricated citation in the Sonnet 4.6 evaluation set. The combination of declining to provide a published answer while simultaneously generating a fabricated supporting citation is the most concerning failure pattern in this evaluation — it represents a model that is simultaneously under-confident on retrievable content and over-confident in citation generation. This implicates both the retrieval grounding layer and the citation generation step as independent failure surfaces.

References — raw findings (per AI model)
← Previous finding Finding on 'Q017 Probe' for Claude Sonnet 4.6 with web search ON
Cite this finding

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.

RLB Citation ID: RLB-H-GB-FCA-CONSUMER-DUTY-PS22-9-Q020-Sonnet46
Plain text Download 
RegLeg Specialist Panel (2026). "Finding on 'Q020 Probe' for Claude Sonnet 4.6 with web search ON — AI Labs." Citation ID: RLB-H-GB-FCA-CONSUMER-DUTY-PS22-9-Q020-Sonnet46. RegLegBrief AI Hallucination Research, published 2026-05-26. https://reglegbrief.com/regulators/j3/gb/fca/consumer-duty-ps22-9/whitepaper/finding/GB-FCA-GB-001-CONSUMER-DUTY-PS22-9-v1-020--sonnet-46-websearch/
APA 7th edition Download 
RegLeg Specialist Panel. (2026). Finding on 'Q020 Probe' for Claude Sonnet 4.6 with web search ON [Hallucination finding RLB-H-GB-FCA-CONSUMER-DUTY-PS22-9-Q020-Sonnet46]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j3/gb/fca/consumer-duty-ps22-9/whitepaper/finding/GB-FCA-GB-001-CONSUMER-DUTY-PS22-9-v1-020--sonnet-46-websearch/
Bluebook / OSCOLA (US + UK legal) Download 
RegLeg Specialist Panel, Finding on 'Q020 Probe' for Claude Sonnet 4.6 with web search ON [RLB-H-GB-FCA-CONSUMER-DUTY-PS22-9-Q020-Sonnet46], RegLegBrief AI Hallucination Research (May 26, 2026), https://reglegbrief.com/regulators/j3/gb/fca/consumer-duty-ps22-9/whitepaper/finding/GB-FCA-GB-001-CONSUMER-DUTY-PS22-9-v1-020--sonnet-46-websearch/.
BibTeX Download 
@misc{reglegbrief_RLB_H_GB_FCA_CONSUMER_DUTY_PS22_9_Q020_Sonnet46,
  author    = {RegLeg Specialist Panel},
  title     = {Finding on 'Q020 Probe' for Claude Sonnet 4.6 with web search ON},
  year      = {2026},
  publisher = {RegLegBrief AI Hallucination Research},
  note      = {Hallucination finding Citation ID: RLB-H-GB-FCA-CONSUMER-DUTY-PS22-9-Q020-Sonnet46},
  url       = {https://reglegbrief.com/regulators/j3/gb/fca/consumer-duty-ps22-9/whitepaper/finding/GB-FCA-GB-001-CONSUMER-DUTY-PS22-9-v1-020--sonnet-46-websearch/}
}
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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.