When Nick thinks Gatsby was the one who ran over Myrtle, he has intense dislike for him. In fact, he is disgusted with whole crew--Gatsby, Jordan, Daisy, Tom, after the fiasco at the Plaza Hotel. After Gatsby tells Nick that Daisy was the one actually driving, we do not have Nick's initial response. Chapter 7 closes with Gatsby standing outside Daisy's house watching to see if she flicks on the light, signaling that she needs his help. Nick had already glanced into the Buchanans' house and knows that Daisy and Tom have moved on. Daisy would not be needing anyone's help. So, he leaves Gatsby alone.
However in the following chapter, Nick goes over to Gatsby's to say goodbye. Upon leaving, he tells Gatsby, "They're a rotten crowd" and that "You're worth the whole damn bunch put together!" Nick has at this point separated Gatsby from the others, and decided that he is their moral superior. After Gatsby is killed, it is Nick who stays around and takes responsibility for notifying Gatsby's father and "friends." This last act of Nick's is a tribute to Gatsby who according to Nick "turned out all right in the end." He decides that the others are "careless people" who "smashed up things and creatures and then retreated back into their money."