I didn't want to suggest that iOS is insecure because Android systems are. For Android we know most of them are hopeless, on iOS it's security by obscurity all the way with just a generally good "track record".

Well, they patched something. Maybe they just patched the firmware image that is loaded onto the chipset on boot and there was no privilege escalation onto the iOS application processor. But if there was, the obscurity means criminals can easily look at the patch to see what it was and exploit that while the public knows nothing.