Level 3 and Cogent have worked it out. Neither the service disruption and nor the use of your own customers as hostages evidence a mature industry that has worked out the contracting methods and terms that would avoid these two unendurable outcomes. Nevertheless, the parties did reach a private accommodation, without the intervention of a regulator. Furthermore, the continual rentseeking and manipulation that regulated interconnection was avoided.
I would expect that you don't need but one Level 3-Cogent service disruption for it to never happen again. The business and reputational effects on both parties were horrendous. Such derision usually makes coming to an agreement much easier.