A refund is never recorded twice

A card refund recorded by hand could be counted a second time by the sweep that checks for refunds we missed, because it could not tell the two were the same one. A booking could then show more refunded than was ever paid.

One refund, one line — a refund entered by staff now carries the card payment it undoes, so nothing can mistake it for a second refund.
When it cannot be sure, it asks — rather than record a refund it cannot rule out as a duplicate, the check now leaves it for a person and says so.