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 provider 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. The automation brief named Round 11, but the inspected archive ended at Round 24, so this is Round 25, sequential.

• 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 29, Round 28, Round 27, Round 26.