The author of a controversial book into sectarian killings in Cork has acknowledged that there are flaws in his research, including the incorrect transcription of at least one original document cited in the work.

However, Gerard Murphy, author of The Year of Disappearances: Political Killings in Cork 1921-1922, has strongly defended the accuracy of his conclusions, including his claim that members of the "old" IRA in the city killed three Protestant teenagers in July 1921.

This is identified by him as a key event which prompted the subsequent murder by the IRA of dozens of Protestant and unionist Cork citizens, in effect leading to a "land grab" and the collapse of the Protestant population of the city. The killings ended with the entrance of the Free State army into Cork in August 1922.

However, responding to an analysis of the original source material conducted by historian and author Padraig Ó Ruairc, Murphy accepted that he had incorrectly transcribed a section of an intelligence report from the IRA's Cork
No 1 Brigade which Ó Ruairc claimed "completely changed the meaning of the sentence".

Murphy said this was "merely a genuine error on my part. I just misread the sentence and it was not part of some conspiracy to denigrate the Republic." He also acknowledged he had incorrectly described four British soldiers killed the night before the truce as "teenagers" when in fact they were all in their 20s.