Bloomberg has looked into what really went wrong with iOS 8.0.1 and who is accountable for the whole mess. Their report points the finger at a QA manager who in the past had overseen quality control for Apple Maps project before its launch.
According to Bloomberg,
The same person at Apple was in charge of catching problems before both products were released. [...] the mid-level manager overseeing quality assurance for Apple’s iOS mobile-software group, was also in charge of quality control for maps, according to people familiar with Apple’s management structure.