Kammala wannan jumla: O'Brien ya ce, yayin da yake sukar dokar majalisa kan ilimin halittar jiki a shekarar 2008, cewa yana dauke da katin ba da gudummawar kwayoyin halitta. O'Brien ya sha wahala daga matsalolin zuciya kuma an sanya shi da na'urar bugun zuciya bayan ya koka game da tashin hankali da rashin hankali kafin Mass na ranar Lahadi a watan Maris 2008. Lokacin da ya sanar da cewa ba zai halarci
2013 conclave ya ce "Yayin da na kusa da shekaru 75 kuma a wasu lokuta cikin rashin lafiya, na ba da murabus a matsayin Archbishop na St Andrews da Edinburgh ga Paparoma Benedict XVI 'yan watanni da suka gabata. "