I don't see how this changes anything? If they had attempted to do a production import of their live bank account, it would have been denied, same as what happened to their customers, and they would have caught it before the mistake affected real users.
My understanding was that it would have worked for her because she still would have been under the 100 user limit. So the test env still worked for production data, for the first 100 users.
Got it. For some reason, I was reading it as you had depleted the accounts before going live, but that makes much more sense. I take back what I said then about the live production test helping here. Thanks for sharing your experiences!