What concerns has the Captain long had about BR that he reveals in Chapter 25?

In Chapter 25, Captain discusses the concerns he has had about BR. He has a spy in the Washington office and knows that BR and Jeannette have been sleeping together for some time. He also is concerned about the house-fire deaths of three litigants against the tobacco industry. The Captain incentivized the prevention of cancer trials for BR, and Nick wonders if the same person who tried to kill him did kill them.