Often our first concern in conflict is proving our innocence. We are blinded by self-preservation and fear. We do not want to take blame or responsibility beyond the little part that we own. We think that paying our pittance is enough. Where would we be if Jesus had that attitude towards the world?
And if someone wants to sue you and take your tunic, let him have your cloak as well.
Lawsuits have been around for millennia. The goal is to repay those who have been mistreated and faced great loss. When you are sued or face the demand to repay someone, start with a willingness to do everything you can and more to restore peace.
A tunic would be comparable to your shirt. A cloak was the outer garment that kept a person warm at night. In Jewish law you could sue for a tunic, but not for a cloak. It was recognizing that the offender should not have to freeze at night. There is respect for basic human rights.
For the price of a winter coat, you may restore a broken relationship. The other has experienced loss because of you. Give them back more than they ask for or deserve.
If you are primarily interested in proving that you are always right, you will miss the opportunity to understand the nature of love. Love keeps no record of wrong and is patient. Your love for an enemy is a greater reflection of God’s presence than holding your ground as a matter of principle. If you are to make a mistake in these matters, err on the side of grace. Can you be judged for having too much mercy?