One of the challenges as a reader is not just to get with the rewinding of time but also to try and work out the narrative voice. It seems to be coming from the translator Alex who is charged with taking Foer to trace his family story.
But in between there are parts of the historical family tree story that are clearly being told by Foer. This divided voice creates the chance for humour and for the author to have a pop at himself ands some of the Jewish stereotypes.
But this is not just about providing different views of the story but also because Foer is playing with language and drawing out the prospect and possibilities of some deliberate misunderstanding.