The woman did not make an excuse for what she had done. She realized the first of eternal life through Jesus Christ. The woman called Jesus Lord. Not teacher, but Lord. She caught a glimpse of His righteousness and the cleansing power behind it.
People often make excuses of their sin.
Jesus had worked in this woman's heart. The Lord did not condone her sin, but He gave her the free gift of righteousness. When God's righteousness is in our midst, our accusers will leave. We do not need to live in the effects of the past, for this righteousness has been imputed to us, not based on our performance, but upon God's grace. Abraham believed God, and it was counted unto him for righteousness.