Also, I thought a couple more interesting passages in the book in "The Galileo Seven" section were what both Nimoy and Marshall (Boma) said. Nimoy said that it was extremely hard for him in that episode as far as acting goes because he was acting alone; without Shatner to play off of. He really realized in that episode how important his interaction with Shatner was to the success of the character.
Don Marshall recalls how the director wanted him to play the role of Boma as a "James Dean Type" character; brooding around. This portrayal can be seen in the scene when Latimer is killed (which is one of the first scenes filmed with Marshall). Boma is in the back brooding with his back to the action (and camera). Don Marshall said in the book that he was frustrated with the director because Marshall didn't feel that his character would act that way. Nimoy could tell that something was wrong with Marshall and when Marshall told Nimoy that he didn't feel the character was acting like a professional would; Nimoy told him to play the character as he thought it should be and that Nimoy would handle the director; which apparently he did. After reading the book I will always notice how different Boma was acting in that scene when Latimer was killed.