Does anyone know the mechanism by which Chase/Cartera knows an item has been returned and thus should deduct bonus shopping miles previously given?

I had bought Master's golf tickets this year through a site offering 7x cash back. Merchant confirmed the order (via phone), my credit card was charged, and I made close to 40k UR points from it. Two days later (and only 3 days before the event) they call me and tell me "sorry, the inventory source behind those tickets you bought is not standing by the order". Merchant has a "guarantee" but when you read the T&C's, they only have to refund your money if they can't come through on the tickets. So they credited my card back. For about 6 weeks the UR points remained in my account, and I didn't feel bad about it because I viewed it as the merchant screwing me over and thus I was happy to have benefitted from it somehow. After ~6 weeks, though, the UR points were reversed. I sent Chase a SM explaining that I didn't return the merchandise, the merchant simply failed to deliver on their obligation, that I thought the points should remain mine as a cost of doing business (marketing cost) to the merchant. They didn't buy that.

Anyway, the question coming out of all this is what mechanism is used by Cartera/Chase to post points, and is that any different than the mechanism used to refund points? I'm wondering if it is all merchant-reported on both posting and refunding, or is the posting of points based on merchant reporting but the refund tied to Chase credit card activity (i.e. seeing the reversal of the transaction that points posted for).

Realized that is a long-winded question but interested if anyone has inside knowledge.