An external, deterministic, model-free grounding audit of the Rafe and Das (2026) helmet-abstention benchmark (1, 464 emergency-department injury narratives). A model-free gate re-reads each note against a sealed schema and returns a three-valued verdict; it reproduces the benchmark's separation between fabricating and abstaining models with no model in the loop, exposes nine likely gold-coding slips, and shows that a single change of prompt wording moves even a frontier model into fabrication. Version 2 corrects version 1, which contained the report only and described a harness, data, and per-cell outputs as released that were not in fact included. This version includes the evaluation harness, the Rafe and Das data as used (CC BY 4. 0), and the complete per-cell outputs, and adds the adversarial negation-and-scope study the report named as its natural next step: the sealed schema's false-grounded rate under adversarial cancellation is 27 to 34 percent (development and held-out), reduced to about 5 percent by a candidate scope-hardened schema (not yet sealed), benchmarked against NegEx, ConText, and a natural-language-inference baseline; the benign-corpus false-grounded rate is zero at an effective sample of about fourteen (Wilson upper bound near 20 percent), and the nine flagged cases are gold-coding divergences. Withheld under UK patent application GB2606072. 3, pending the doctoral thesis: the OFM-PBL core (the verdict-folding engine) and the sealed schema. The harness scripts import them and are provided for inspection; every reported figure is verifiable against the released per-cell outputs, but verdicts cannot be re-derived from raw notes without the withheld core and schema. See the Version 2 note in the report, DEPOSITREADME. md, and DATA. md. Version 2. 1 corrects an attribution error in the negation-and-scope materials: two model-performed second-coding exercises were described as independent human coding. Both were performed by general-purpose language-model sub-agents of the same family that authored the gold labels; their perfect agreement is self-consistency, not construct validity, and the reliability framing is withdrawn. Blinding is retained; the separate three-vendor nine-case re-adjudication is unaffected; no figure or verdict changes.
David Antonio Tomé (Mon,) studied this question.