even a thief has some justification; everyone has their reasons
Proverb meaning that even wrongdoers can find excuses for their actions; often used to acknowledge that there are two sides to every story.
Hearing his side of the story, I start to think that even a thief has his reasons.
A traditional Japanese proverb; the exact origin is uncertain, but it reflects a common folk wisdom that even those in the wrong can find some justification.