Now that we have pulled back sufficiently far from the near “destruction of the modern financial system” — as the former Treasury Secretary Henry Paulson described the events of 2008 in his new memoir, “On The Brink” — to focus on how to prevent such a calamity from recurring, the time has come to hear from those players in the drama who really know what happened and why. Until people such as Warren Spector, the former co-president and head of the fixed-income division at Bear Stearns, and Dan Jester, a mysterious former Goldman Sachs banker turned Treasury official — among...