>if they had been compromised then the hacker could have leaked far more than one random card, and the fraudster could have kept trying numbers until one worked

>if they had been compromised then the hacker could have leaked far more than one random card, and the fraudster could have kept trying numbers until one worked. But they couldn't. You repeat this a few times, but you have no evidence for that. At most, you know that no one tried to use more than one of your credit card numbers.