What is the main conflict in Point of Impact by Stephen Hunter?

The story opens with Bob Lee Swagger sitting uncomfortably in the sleet at exactly the point where he will encounter a trophy buck called "Tim" by the locals. He waits for hours, refuses to allow his teeth to chatter, and makes the perfect shot when the monster buck appears. The buck falls and Bob watches the downed animal, noting the fear and betrayal in its eyes, then cuts the antlers off and stands back, now certain that the buck won't be taken merely as a trophy.