Until employers cease to see workers as an expense, and start to see them as humans beings, there will never be peace in the workplace.
We take responsibility for our mistakes and learn how not to do that again. But more importantly we share that learning or better still play a role in a bigger learning exercise, so that nobody else has to make that mistake again.
Management are victims of the work systems as much as anyone else. Don’t blame the person, (help them) fix the system.
There is much debate about estimates. I can see the necessity. What matters is the culture around them.