Today, senior reporter Max Mason on how two former 'besties' turned on each other after their multi-million dollar fraud unravelled, and why it took NAB years to uncover their lucrative scheme. And legal editor Michael Pelly gives his take on what it means for white-collar crime in Australia.Further reading:Former NAB chief of staff jailed for fraud The former chief of staff to NAB chief executives Andrew Thorburn and Cameron Clyne has been sentenced to a combined eight years in prison for participating in a multimillion-dollar fraud scheme.Lavish lunches key to planning NAB fraud Rosemary Rogers, the former chief of staff to NAB chief executives Andrew Thorburn and Cameron Clyne, and Helen Rosamond, the owner of events company Human Group, met for lavish lunches in Sydney every few weeks to plan their alleged fraud of the big four bank, the Crown alleges.See omnystudio.com/listener for privacy information.