What is the author's style in The Killing Zone: My Life in the Vietnam War by Frederick Downs?

The book is autobiographical about the author's experiences in the Vietnam War, and as a whole is in the 1st person point of view. There are points in the book where the author describes in depth what other soldiers are experiencing. For example, on P. 93-95, there is a detailed description of what Fouel, the former Vietcong, does when he confronts Vietcong soldiers. However, the reader never gets inside Fouel's thoughts, or anyone else's except for Lt. Downs.