You've never written a bug that wasn't discovered until production? I certainly have, and given that I still haven't found the secret to never doing so again, I

You've never written a bug that wasn't discovered until production? I certainly have, and given that I still haven't found the secret to never doing so again, I also build systems that are updatable with as little friction as possible. I don't see how the parent failed to take responsibility. They were responsible for the bug. Apple was responsible for the delay in the fix.