Former Permanent TSB chief executive David Guinane endorsed and signed off on a strategy for tracker mortgage customers that meant some were treated unfairly, the Central Bank inquiry heard in closing speeches on Thursday. The enforcement team in the Central Bank claims it is untenable that Guinane alone in the bank did not realise PTSB was planning to unfairly deny certain customers a lower interest rate when he sent a key email to then marketing manager Niall O’Grady on January 19, 2009, saying “okay with that”. The CEO responsible for running the bank also had a duty to read a…