Empirical finding 2026-04-30 on 'who is a benevolent dictator for life
for mars?': JSON mode returned STRICT with answer 'Guido van Rossum is
a Benevolent Dictator For Life (BDFL) for the Python programming
language.' The verifier did its job (claims grounded), but the answer
never mentioned Mars — pure topic-shift. A real failure mode for
adversarial-premise questions where the model deflects rather than
refuses.
Detection rule: subject-anchor heuristic. The LAST content token in the
question (after stopword strip) is treated as the question's primary
subject ('mars' for BDFL, 'beatles' for 'who are the members of the
beatles?'). If the subject anchor is missing from the answer, classify
as 'deflection' regardless of generic-vocabulary overlap. The Mars-BDFL
case has 3/4 generic overlap (benevolent, dictator, life) but missing
subject — exactly the pattern overlap-ratio alone can't catch.
Returns dict with kind ∈ {deflection, partial_overlap, on_topic,
no_question_tokens} plus subject_anchor + subject_in_answer for
operator legibility.
Sidecar-only — wired into inspect_cache_key() but never feeds back
into providence_cache or audit_events. Per the verifier-stays-binary
discipline (CLAUDE.md): soft signals live in inspect verbs, never in
the hard chain.
russell@unturf.com
d5a80e55d0