A very very unnecessary detail: "She was Estonian"

Two years ago I discussed Dirk Bogarde's visit to Bergen Belsen, his biographer's doubts, and the unexpected confirmation from an independent source. Go here to watch that. https://www.youtube.com/watch?v=zW1nLyn70ZE&t=922sI've been revisiting that topic recently in my research, and I was struck by an unnecessary detail in one of Bogarde's interviews that all by itself is noteworthy evidence for the credibility of his story. Discussing it gives me an opportunity to talk a bit more about what unnecessary details really are.Here is Bogarde's interview:https://www.youtube.com/watch?v=6QaNCbig82Q