It's a mistake to think when something goes wrong there must be a single person (or rule) to blame. If a program does not behave according to spec, then presumably the programmer made a mistake, unless satisfying the spec is impossible. But if the defect made it past qa, then the qa must be imperfect also. And if your programmers and qa team are all a bunch of fuckups, maybe your hiring process is flawed also. And so on.