nolans actions and what he actually wants for himself and his son are very different things. is it possible that he knew saying things like debbie was a “pet” would drive mark away. because more than he hated having to possibly leave his life on earth he hated the idea that his son would have to experience that too? and so just half assed the attempt to convince him?
he was trying to both convince mark and himself that thi wa the right thing to do. hi experience on earth fighting violently with thousands of years of indonctrination, and ultimately winning.