I think that the only way that both experiences can make sense is to understand that Changez is right that he is a "lover" of America. In being "a lover" and not "in love," Changez is readily admitting that there is a portion of his psyche that is hurt by what has happened between he and America. Changez is able and ready to admit that he is bearing some level of hurt and dismay from his relationship with America. He is a "lover," meaning that he has experienced some level of being relegating to the periphery. Certainly, this would account for the smile creeping across his face when he sees the towers fall. He smiles not because he hates America, but rather his "lover" (America) has experienced some of the same pain and hurt that he has experienced. His smile is because he understands that he and his "lover" are both recipients of pain. He is a "lover" of America, which means that he cannot really extricate himself from America. It is for this reason that while he might profess to not like America, he talks about it for hours on end with the America with the American. He is a "lover" of America. This means that he has different emotions towards it. One of these emotions is hurt and pain, and for this reason, he smiles at the the 9.11 attacks. Yet, his smile is not out of malice as much as it is identification that for a moment, the object of his love has experienced the same type of feelings that he endures.