Whether you think that has been proven or not, all of that is theoretically provable, and my book basically makes the case that it has been proven, though I will say that I don't go into detail on every single sentence and every single word of every Gospel. I provide over a dozen examples with some lists that highlight dozens more examples, but, yes its true you can still find sentences among the Gospels that I haven't shown explicitly come from some known literary source. So I guess one could always say that some phrase whose provenance hasn't been traced to scripture or an epistle may have "been real words of Jesus". But anyway.