It can't be reduced to one error. A life can not be defined by one mistake…no matter how big. You have to take the measure of the whole life, the whole story, the whole journey and put it all in context. Otherwise you have the most distorted of views of a person, a life, a journey and you miss the lesson.
Those that judge the other by the one error are usually the ones who have flaws to share.
As time has gone on I realize that we learn from the falls. Rarely do we learn from the successes because we are just too busy congratulating ourselves. Only when we fail can we evaluate our actions and grow.
So in the end it is the failure that shapes us and permits us to escape to success.
Embrace the loss. See it as the teacher it is so long as you are willing to go to class and study for and take the exam.
The hero journey always has an element of risk, failure and loss. Without that the hero can never emerge.