Unfortunately, the Zapruder film's dollar value could not be agreed upon using this negotiation technique. It is important to understand the very significant contrast between mediation and arbitration. Mediation is a voluntary act of the negotiating parties. They rely on a mediator to facilitate their negotiations, but the parties retain complete control of their own decision-making processes. A mediator helps keep the process fair, keeps it moving, and may help the parties develop a better understanding of how to negotiate.
Arbitration is quite different.
Once parties agree to place their issues in the hands of arbitrators, they have given up their rights to make independent decisions about the issues under consideration. The arbitrator or arbitration panel is the decision-maker. In the Zapruder film situation, each side chose one arbitrator, then those two arbitrators chose a third member of the arbitration panel. The arbitrators considered evidence presented by the parties and their experts. While the US Government was prepared to pay one million dollars, the Zapruders wanted thirty million dollars.