In the context of a justice system which recognizes "Truce(s) of Mutually Beneficial Human Relationships" and polycentric-law:
If (a) person-A considers murder as a neutral behavior (b) and engages in murder, then (a+b => c) he has demonstrated an unwillingness to participate in the truce of "not murdering." As such, (d) if Person-A were to be murdered, Person-A is being treated according to the (Ethical) standards which he treats others.
Destruction + Destruction = more destruction
What about arbitration? In short, returning 'destructive' or 'unethical' behaviors with more destructive or unethical behaviors results in a greater net-destruction. As such, avoiding further destruction if possible may be a practical, and arbitration offers one such practical solution for avoiding further destruction.
Restitution offers an alternative (amongst others perhaps) which allows someone to restore their "truce status" and demonstrate through action their desire to restore or uphold this truce. Two individuals may settle this dispute privately (a settlement), however due to a variety of situations this is not always possible.
Given an unresolvable dispute, two individuals may agree to follow the decisions of a neutral third party (another person) as a means of resolving the dispute or avoiding physical confrontations. This framework of dispute resolution is typically known as arbitration. Arbitration offers a variety of advantages, allowing someone with less emotional and personal attachment to the outcome, to determine (to the best of his ability) the best way to resolve the given situation from a more neutral and less incentive perspective.
One can always refuse arbitration. As a result, they may suffer a variety of consequences. One might choose to pursue the least destructive and most effective means of "punishing" the individual, such as online ratings, blacklisting, negative credit reports, and public records of the incident and refusal to agree to arbitration. In future dealings, individuals may be more cautious and less likely to conduct business with a person who refused arbitration.
Another possibility of refusing arbitration, and consistent with contract-theory, is the possible consequence whereby a violator finds his own person and property being *"violated"* according to the same standards they treated others. A thief may find armed guards on "his property" repossessing valuable items, or a murderer may be terminated.