It's a quite partial evidence in favour of Sony, but as much partial look those against it, and Sony already made some admissions, but not of total guilt, so its liability could be mitigated. The most negative scenario could suggest unforgivable sloppiness, this one suggests more a slip in the security protocols or in their application.
Sony must not rest, anyway, it's obvious something went terribly wrong, either culpably or not, a revision of protocols and their application is urgently needed. Once Sony will have its network restored and its safety certified by specialized firms, it will still have to bear the burden of insurance and possible damages to users, but it will be able to offer a more reliable and secure online service, with a new image possibly clearer than competitors, having undergone such a harsh test. Indeed it's quite likely that once Sony will have its service restored, reviewed and certified, competitors too will be forced to do the same even before or without enduring an attack so fierce.
