The real issue is not what Luke believes or what kind of words he has or has not used, but what Jesus actually said
hmike...Luke has taken Matt and Mark and reformulated it according to his personal christology. He even seems to be specifically refuting Matt in his introduction where he tells his christian audience Theophilus that he needed to hear a corrected 'truthful' version of the Jesus story. He never 'quotes' anyone, he is using the other versions and tweaking them. The author of Acts (same person as edited Luke?) likewise never 'quotes' Jesus nor even pretends to. The book is an artificial reconstruction of Christain origins designed to unite the very different cults of Christ and Jesus of the 2nd century. The whole search for the "historical jesus" is becoming more futile as we understand the literary nature of these books.