As I understand it the key to the blameless and just culture is to keep going to the bottom of it: "You cut corners. You were incentivized to cut corners. Why? Why do those incentives exist? What can we do to remove those incentives in the future?"

The core of the philosophy is assuming people come to work to do a good job, and when they don't do a good job, there are reasonable explanations that involve people making locally rational decisions. The goal is to make the system stable in a way that making locally rational decisions translates to globally good decisions.