Continuity mistake: While in the courtroom Bull walks up to Christine, Dan, and Harry. The shot changes and he walks up to them again.
Continuity mistake: After the first courtroom scene people are walking out. The right door is open and the left closed. The shot changes and now the right is closed and the left is open.
Answer: It's possible when Harry called the military, he implied that the book contained sensitive information, seeing as how many government and military officials were part of the client list.
I thought it was because he developed feelings for the madam and couldn't bring himself to turn her in.