In chapter seven, when Gatsby's innocence is first revealed in a phone call, the reader is left not knowing Nick's emotional reaction to the news; however by chapter eight (the next day), it is clear he has come to see Gatsby as something of a romantic hero. Nick's admiration comes in spite of his dislike for Gatsby's criminal enterprises.
Myrtle's death in the car accident comes at the end of a long day where Nick truly sees the group - Tom, Daisy, Myrtle and Gatsby - for their shallow and materialistic way of living. On a very hot summer day, Tom confronts Gatsby about the affair he is having with Daisy and there is an ugly scene. After Myrtle's death, Tom invites Nick back home but he is disgusted with them and the morally empty society they represent. "I'd be damned if I'd go in; I'd had enough of them for one day," he tells the reader as narrator.
Nick includes Gatsby in his unfavorable summation of their world until later, waiting on a cab to take him home. He meets and questions Gatsby and learns that it was Daisy, in fact, who had been at the wheel when the car struck Myrtle. At the end of chapter seven, he leaves Gatsby in a solitary vigil on Daisy's front lawn, ready to help in case she needed it.
In chapter eight, as Nick leaves Gatsby at his mansion the next day, he tells him that he is, "worth the whole damn bunch put together." It is clear that despite his disapproval of Gatsby's bootlegging and criminality, he is impressed by his romantic devotion to Daisy, even though Daisy is revealed to be shallow and materialistic and unworthy of it.