One solution would be for (some) individual contracts to be programmed to have "curators" with an expanded role. These curators would have dictatorial powers (via a supermajority vote of the curators) to nullify and replace the entire contract. However, they would promise to do this only in case of a genuine software bug, or if ordered to do so by a court with jurisdiction over them, not for any other reason. There would be many curators. Many of them would be professional curators, similar to professional accountants or trust executors, who work for huge firms which, like Big Four accounting firms, have a lot to lose if any of their members are caught misusing their power.