Bertram Copeland Rumfoord—who originally appears in another of Vonnegut's books, The Sirens of Titan (1959)—is an incredibly energetic 70-year-old with a hottie 23-three-year-old wife.
He winds up breaking a leg in a skiing accident in Vermont at the same time that Billy has his plane crash. The two share a hospital room. Rumfoord is working on a short history of the U.S. Air Force, and he is particularly interested in researching the raid on Dresden. But he cannot believe that Billy was actually there because he is so certain Billy is a useless waste of space, a vegetable who is just repeating words he hears Rumfoord saying.
The thing about Rumfoord is that he is a kind of superman: an athletic, respected Harvard professor who cannot believe that anyone as pathetic as Billy could have anything to contribute to the world. Rumfoord eventually decides that Billy was probably at Dresden, but he isn't interested in talking to him about his experiences.
Instead, he insists on repeating over and over that the firebombing was necessary, even though Billy never said that it wasn't. Rumfoord is paranoid about bleeding hearts pretending that the Air Force might have done the wrong thing by causing so many civilian deaths. He wants to celebrate the Dresden firebombing as "a howling success" (9.10.5).