Gill's own book, The House on Schellberg Street, examines just what ordinary young German people may have known during Hitler's rise to power and throughout World War Two. (Many really did not want to be at war with Britain incidentally. As well as having friends here, well we Brits are often known as Anglo-Saxons and of course the Saxons were from Saxony which is in Germany. Our history goes back a very long way).
So what then is "honest" writing? Is it just strict non-fiction based on verifiable fact? I don't think so. It is writing which comes from the heart of the author and which conveys an important message (and without preaching. To Kill a Mockingbird does this superbly. The horror of racism is conveyed brilliantly). It is the author writing true to their characters regardless of how horrible or nice they are. It can be the author sticking to their guns at times when it comes to how they want "their people" to be portrayed.