Among the first hints that all was not well at Enron was the moment in April 2001 when Jeffrey Skilling, then the US energy trader’s chief executive, called a persistent analyst an “asshole” during a conference call. That outburst and Thursday’s guilty verdicts on Skilling and Kenneth Lay, Enron’s former chairman, neatly book-end a five-year period that included both the extremes of corporate fraud and the extremes of corporate regulation, in the form of the 2002 Sarbanes-Oxley reform act.

Within hours of Lay and Skilling’s convictions on charges of fraud and conspiracy, Paul Sarbanes, the Democratic senator and co-author of the legislation, issued a statement saying that “Enron was the canary in the mineshaft” and reiterating the importance of the act’s “system of checks and balances” in preventing repeat scandals.