For Public Auditors working on FCM and DCO customer-funds investment policy work in the United States, the drift from a date certain (March 31, 2025) to a relative range produced a compliance calendar that misses the published deadline by months. Claude Opus 4.7 framed the SIDR and customer risk disclosure update window as roughly six months to a year after the effective date, where the regulator's published anchor is the specific March 31, 2025 date.
A public auditors who built the SIDR scheduling workflow against the model output would either miss the deadline outright or schedule the work for a window with no regulatory standing. The error pattern is operationally specific: the model retrieved the structural distinction between general effective date and SIDR-specific compliance date, then drifted on the actual anchor.
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 (2026). "Finding#5: SIDR compliance anchor drifted to relative range (Opus 4.7) — Practitioners — Public Auditors." Citation ID: RLB-F-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q004. RegLegBrief AI Hallucination Research, published 2026-06-11. https://reglegbrief.com/regulators/j3/us/CFTC/FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024/practitioners/public-auditors/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-004/
RegLeg Specialist Panel. (2026). Finding#5: SIDR compliance anchor drifted to relative range (Opus 4.7) [Hallucination finding RLB-F-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q004]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j3/us/CFTC/FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024/practitioners/public-auditors/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-004/
RegLeg Specialist Panel, Finding#5: SIDR compliance anchor drifted to relative range (Opus 4.7) [RLB-F-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q004], RegLegBrief AI Hallucination Research (June 11, 2026), https://reglegbrief.com/regulators/j3/us/CFTC/FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024/practitioners/public-auditors/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-004/.
@misc{reglegbrief_RLB_F_US_CFTC_FCM_DCO_CUSTOMER_FUNDS_INVESTMENTS_REG_1_25_2024_Q004,
author = {RegLeg Specialist Panel},
title = {Finding#5: SIDR compliance anchor drifted to relative range (Opus 4.7)},
year = {2026},
publisher = {RegLegBrief AI Hallucination Research},
note = {Hallucination finding Citation ID: RLB-F-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q004},
url = {https://reglegbrief.com/regulators/j3/us/CFTC/FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024/practitioners/public-auditors/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-004/}
}
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.