Write Don and complain (gold@gwe.net). Being a bigot never seemed to disqualify Robert Byrd from being taken seriously. Spend less time trying to disqualify his opinion because you disagree with the words a 75 year old man uses to describe the Japanese. Spend more time understanding his attitude towards those who write revisionist history.
I would never take seriously an examination of the Civil War that used the term "n----r" except in historical contexts. "Jap" and "Nip" and so forth, similarly, have no place in a serious discussion of the issues. His choice of diction shows he is nothing more than a hardened old bigot, still living in the 1940's.
BINGO. I know several veterans who experienced "Jap" treatment first hand - one being a Bataan survivor. Another fellow piloted an LST bringing Marines into Iwo Jima. None of them are as enlightened as modern professors at Universities.