also from ^ article on Lockheed Martin Corp space shuttle software group ...

  Importantly, the group avoids blaming people for errors. 
  The process assumes blame - and it's the process that is 
  analyzed to discover why and how an error got through. 

  At the same time, accountability is a team concept: 
  no one person is ever solely responsible for writing or 
  inspecting code. "You don't get punished for making errors," 
  says Marjorie Seiter, a senior member of the technical staff. 
  "If I make a mistake, and others reviewed my work, then I'm
  not alone. I'm not being blamed for this."