When Silence Looks Like Stability: Detecting Missing Change Evidence in Collaborative AI Systems

Can an AI assurance system distinguish a genuinely quiet authority from a broken, delayed, stale, selectively silent, or common-mode observation path?

Round 25 asks whether an AI assurance system can distinguish a genuinely quiet authority from a broken, delayed, stale, selectively silent, or common-mode observation path, and proposes the Silence-Aware Coverage Protocol (SACP). D25-A is an authored-fixture conformance diagnostic, not production evidence. On 80 authored traces (60 positive gaps, 20 negative controls), SACP alerted on 55 of 60 gaps and 0 of 20 controls: TP=55/60, FP=0/20, trace recall 0.9167, claim-weighted recall 0.8944. The five intentional misses were two selective non-emission cases with no independent external commitment and three verifier common-mode failures with no independent challenge path. No production incidents were sampled, no independent reviewer labelled the traces, no language model or external-service API was called, and no new Encevra answer benchmark was run. D25-A: Executed (bounded diagnostic). E25-B and H25-1 to H25-10: Proposed. Architecture impact: None. Production impact: None.

• On 80 authored traces, SACP alerted on 55 of 60 gap traces and none of the 20 negative controls (trace recall 0.9167, precision 1.0000, claim-weighted recall 0.8944). Revalidate-all achieved 1.0000 recall but alerted on all 20 negative controls and created 400 claim-review tasks, compared with 161 for SACP. A sequence-only policy falsely alerted on all five benign-reordering controls. These numbers show that the implementation conforms to the authored distinctions. They do not estimate production precision, recall, incident prevalence, reliability, cost, or user impact.

• D25-A Adversarial-omission authored conformance diagnostic (D25-A) Executed (bounded diagnostic)
• E25-B Prospective fixed-budget multi-authority silence-coverage trial with hidden independent adjudication Proposed

• H25-1 Gap recall: At fixed total monitoring and revalidation budget, SACP reduces independently adjudicated affected-claim gap misses versus receipts-only, heartbeat-only, checkpoint-sequence, and periodic-expiry baselines.
• H25-2 Availability: SACP preserves more correctly current claim-hours than revalidate-all while staying within a preregistered non-inferiority margin for affected-claim gap recall.
• H25-3 Lineage: Removing root-lineage checks increases misses for mirrored/common-origin failures without reducing detection of independently rooted conflicts.
• H25-4 Maturity window: Removing the reorder maturity window increases false observation gaps on delayed but complete streams.
• H25-5 Challenges: Removing challenge canaries increases detection delay for observer crashes and stale checkpoint freezes.
• H25-6 Independent reconciliation: Removing separately rooted reconciliation increases misses for selective non-emission and equivocation.
• H25-7 Expectation weighting: At the same total challenge count, authority-specific expectation-weighted scheduling improves gap recall or detection delay without increasing false suspicion versus uniform scheduling.
• H25-8 Scoped state: Claim-scoped gap projection reduces unnecessary claim withdrawal versus authority-wide or registry-wide fail-closed policies without increasing stale-claim escape.
• H25-9 User-facing honesty: Explicit `unknown_observation_gap` status reduces unsupported current claims without causing more abandonment or misunderstanding than a generic stale label in a blinded review.
• H25-10 Complexity: A simpler checkpoint-sequence-plus-end-to-end-probe policy matches SACP on safety, availability, and cost. Support for this hypothesis would reject the need for full SACP.

Production impact: None. SACP was not installed, and no release gate, retention policy, or deployment behavior changed.

• Does SACP reduce independently adjudicated affected-claim gap misses at fixed total budget in a preregistered prospective multi-authority trial (E25-B)?

Builds on Round 24, Round 23. Continued in Round 38, Round 37, Round 29, Round 28, Round 27, Round 26.