Michael Fingleton’s voice was raspy but unmistakable.  It was late April 2018 and I’d rung him after hearing he was unwell. Fingleton acknowledged his health was poor, but he was sparky. I’d co-written a book and made a documentary about the building society’s managing director, Fingers,with the journalist Richard Curran in 2013, so I wasn’t expecting a warm greeting. But he was friendly. “Everybody told me not to talk to you,” he said.  At the time we spoke, Fingleton was being sued by the liquidators of his former bank IBRC. They were looking for €6 billion, the most any individual has…