This is exactly why human error is not a valid answer in the 5-why process. A good company will try to identify what makes this more likely and remove the root

This is exactly why human error is not a valid answer in the 5-why process. A good company will try to identify what makes this more likely and remove the root cause. A bad company will find someone to blame. Reading up on Deming's work and the Toyota Production System, is eye-opening if you haven't read it. The methods to improve are publicized, you only have to implement them.