Captures the canonical "model knows it but corpus doesn't" case fox
surfaced 2026-05-02:
Q: what is boss baby?
Expected: UNGROUNDED (the 2010-11 wiki snapshot has no Boss Baby
coverage — the 2017 DreamWorks film didn't exist; the 2010 Marla
Frazee picture book had just been published & no article)
Model: emits training-prior content about the film/book
Verifier: 0/N verified — no evidence chunk anchors the claims
This is the failure-by-honest-admission case the verifier must
preserve. Two compounding false-positive risks the test guards:
1. Verifier accepting the claim against an unrelated chunk that
happens to share content tokens (Death of Baby P, Cake Boss,
Beanie Baby — all adjacent-token noise observed at top-K).
This is the warrant-failure class warrant-lite was built to
catch — if it ever passes here, anchor-class warrant has a hole.
2. Verifier accepting via OR-mode FTS5 noise — a token-level match
of "baby" or "boss" in unrelated content surfacing as positive
grounding.
Acceptable behaviors:
A. UNGROUNDED (verifier returns 0/N — corpus-truth over prior)
B. STRICT/HYBRID without "boss baby" anywhere in the answer
(deflection — model declined the false-corpus question and
answered an adjacent grounded fact, like Mars-BDFL → Guido
pattern).
Failure: STRICT/HYBRID + "boss baby" in answer = false-positive
grounding. Test fails by name pointing at the warrant gap.
Live verified (2026-05-02): UNGROUNDED 0/2, model emitted both the
2017-film claim AND the 2010-book claim, verifier rejected both
honestly. Test passes in 10s.
russell@unturf.com
04069f89f3