Lawyers for the businessman Denis O’Brien have quizzed human rights lawyer Darragh Mackin as to whether he actually wrote any part of a 2016 report on media ownership in Ireland that criticised businessman Denis O’Brien. On day two of the Belfast-based solicitor’s defamation action against the telecoms tycoon, lawyers for O’Brien challenged his contribution to the study, by reference to emails sent between its various authors and Lynn Boylan, the Sinn Féin MEP who commissioned the report.  Those emails discussed details of publication and suggested sending advance copies under embargo to Colm O’Mongáin of RTÉ, and also to Roy Greenslade…