“JM at his best”, the WhatsApp message said of bloodstock magnate John Magnier’s handshake deal to buy the Barne Estate for €15 million on the evening of August 22, 2023. Under cross examination on week three of the Barne court battle, Coolmore accountant Jerome Casey didn’t immediately recognise himself as the author of the text. “I didn’t say that.”  He then conceded just as quickly that he must have sent it. Casey is an old hand at the Coolmore Estate who has spent years working very closely with John Magnier and his wife on a myriad of different projects, the…