It would have had to be refund. The hacker could t initiate a chargeback from knowing the merchant's stripe keys. Seriously doubt it was a competitor. The risks of hiring someone to commit felons against your competitors just isn't worth it. Especially since the vibe coder seems to be bungling things on their own just fine.
How about you pay more attention to the story? It's not Visa/MasterCard or the customers that got hacked.