It’s extremely hard to catch really smart hackers.
In this particular case and other corporate hacking events, more time than not the source of the hack is internal not some super geek in a basement somewhere around the world.
Why? Hackers operate in the digital domain and supposedly, the digital domain is impossible to secure.
Furthermore, if the problem is insiders, then that problem is not unique to the digital domain. My point is that digital systems are not impossible to secure. Certainly not any more than old technology. Does anyone think paper billing is impossible to attack? Fax is secure?