Earlier quoted context omitted.
No, this was not a good response. It was well written and took responsibility for bad code, but it failed to address the elephant in the room: why were keys not immediately rotated? I've said this a number of times lately, but it bears repeating that the golden rule of security is: If a compromise occurs, assume that everything is compromised. Even if their approach was tested to be perfect, they shouldn't have made…
No, that goes too far the other way. If I have legitimate reason to believe that an exploit does not affect me (especially if it's because I acknowledged its possibility and programmed defensively against it), why would I automatically act as if I were breached too? Your argument is totally correct if I am simply unsure---if I don't know whether an exploit affects me but I suspect it might, I assume the worst and act…
If you have a memory read out of a process that contains sensitive data, you should always assume that the sensitive data was breached, even if you "programmed defensively against it". Period. No exceptions.
They had good reason to believe they were unaffected, which is why they shouldn't have hit the "oh shit, the world is ending" button. But the decision to not roll their keys in the face of a breach was a massively irresponsible one. We have how many years of major bugs to look at? And in how many cases are the likes of Akamai (that is, organizations with theoretical mitigations in place) actually safe when they think they are?
Always, always assume your protections are faulty in a way that a motivated attacker will figure out.