Israel really is in a dispute with Iran. Iran really believes there should not be a Jewish majority state in Palestine. Because of that, people who disagree with Iran, especially people who disagree vehemently, and who intensely identify with Israel have a strong incentive to present Iran in as demonic a light as possible.
When Benny Morris claims Mahmoud Ahmadinejad calls for murder, he is lying, he is making a statement that is a falsehood.
I take it personally: Iran's president, Mahmoud Ahmadinejad, wants to murder me, my family and my people. Day in, day out, he announces the imminent demise of the "Zionist regime," by which he means Israel. And day in, day out, his scientists and technicians are advancing toward the atomic weaponry that will enable him to bring this about.But there is a question of whether he has deluded himself or if he is cynically attempting to mislead or take advantage of the lack of familiarity of his audience. That raises a further question. If a person is driven by some form of intense emotional drive to delude himself, is that more noble than to be aware that one's statements are false and to make them in that knowledge?
Morris absolutely has enough access to information to have accurate reports of Ahmadinejad's statements, and as a researcher can be expected to have the intellectual curiosity to care. It is safe to say that Morris is aware that he is unable to produce an example of Ahmadinejad expressing any desire to murder him, his family or his people.
Does it matter? Not too much. Morris' statement hurts his case more than it helps. Just something to note.