Ferriter also wrote on some of these issues (separate to discussing Hart):
If Hart wrote this would he not be widely criticised for it?
Of course sectarianism had a part to play in the War of Independence. However, Hart made sectarianism the sole motivation for the Dunmanway killings. He consistently made controversial claims without supporting evidence. Furthermore, he completely ignored evidence that contradicted his argument.
Hart was an academic historian. He well knew the methodolgy of his chosen profession. When challenged about his sources he refused to give direct answers. From this I can only deduce that he craved the attention/notoriety his work attracted.
This isn't about knocking him because he was challenging the conventional view of history, there's nothing wrong with that. I've read two of his books, during which there were numerous moments where I sat up and literally said 'fookin hell, that is just wrong'.
I know you haven't read any of his stuff (I wouldn't bother if I was you), In an earlier post in this thread I posted some links to articles which critique his methods. They are well worth a read if you have the time.