An irate phone call with the US construction magnate Maurice Regan over John Magnier’s  €15 million bid for Barne Estate spurred the bloodstock billionaire to drive to the 750-acre estate to try and push through an exclusivity deal, his son-in-law told the High Court today. David Wachman, a retired racehorse trainer, is the husband of Katherine Wachman, a co-plaintiff in proceedings over the contentious sale of the Co Tipperary estate alongside her father, John Magnier, and her brother John Paul.  The 750-acre property is held for the benefit of Richard Thomson-Moore, his sister Alexandra, their children, and their spouses by…