Ah ok. He's talking about reclaiming unclaimed tokens. That's not really a clawback, at least not how I understand the term. This is like an unfinalized lightning transaction that later fails, like with a hold invoice. It's a great feature because it means you aren't sending your money into a black hole.

A clawback (I think the most commonly understood definition of the term) is when you finalize the transaction and then reverse it later. This is how check fraud or credit card fraud works. This is not possible with ecash. Once the token is claimed there is nothing either party can do to reverse that transaction.

The mint can't even act unless the user accused of fraud deanonymizes their ecash token, which they have no incentive to do. Even in that case, the mint can't know for sure which user to reissue it to because they both have the blinded secret. Ecash is too private; the mint knows nothing and can't really act so clawbacks are not possible.

I only recently added the relay index to nostrdb, we should be able to do it now.