Ann: Redflow enters Voluntary Administration, page-120

I’m guessing here, so take this with an appropriately sized chunk of salt. But I don’t think they actually know. I’m guessing that it took some time for the failure to manifest, and they would have needed a similar time to validate their assumptions about cause and fix. They could have had an accelerated testing regime to try to reduce that time, but they still would have needed to wait for the results. (Side note: if they had two units, one with the fix, one without, testing until the latter failed would be a reasonable starting point for validation.)

I’m also guessing that this would be part of the reason why the business wasn’t sold as a going concern; any prospective buyer would have wanted evidence of the root cause and fix. If that wasn’t available, most buyers would nope out.