I also liked this part. It was almost relieving when he punched him. While you have all the confidence in the world in Roland's decision making, you also have to see things from Cuthbert's point of view. After this part I felt like Roland was back on track and back to being a true Gunslinger. It also helped to show that Cuthbert was more than just a wise cracking loud mouth. This part gave him much more sustenance as a character and respect from the reader.