You can’t handle the truth!
Not everyone has the courage or maturity to handle the truth (of having made a mistake). The typical response is to be defensive and accuse the other party of his or faults instead.
The fact of the matter is that if it is the truth, no amount of arguing or retaliation will change the truth.
The truth remains as is.
Let us instead accept our mistake and extract as much learning as we may from the lesson.