As previously covered, encouraging a fail fast way of working is a critical element to good agile engineering practice, it is all well and good saying this but this has to become a real part of the way your business works; as they say, actions speak louder than words. If, for example, we have a manager who thinks that pointing the finger and singling people out when things go wrong is a good motivational technique, then it's going to be very difficult to create an environment where people are willing to put themselves out and try new things. A culture of blame can quickly erode all of the good work done to foster a culture of openness, honesty, collaboration, innovation, and accountability.
Ideally you should have a working environment where when mistakes happen (we're only human and mistakes will happen), instead of the individual(s) being jumped on from on-high, they are encouraged to learn from the mistake, take measures to make sure it doesn't happen again, and move...