The premise of the book - that the camp would have a child of Shmuel's age - is, according to some critics, an unacceptable fabrication that does not reflect the reality of life in the camps. However, John Boyne stated that some Jews under the age of 18 were sent to work for a few months, and then killed. According to statistics from the Labour Assignment Office, Auschwitz-Birkenau contained 619 living male children from one month to fourteen years old on August 30, 1944. On January 14, 1945, 773 male children were registered as living at the camp. "The oldest children were sixteen, and fifty-two were less than eight years of age." "Some children were employed as camp messengers and were treated as a kind of curiosity, while every day an enormous number of children of all ages were killed in the gas chambers."
Rabbi Benjamin Blech said: "This book is not just a lie and not just a fairytale, but a profanation." His chief complaint is that it supports the idea that ordinary people were unaware of the horrors of the Nazis' mass extermination of Jews. He argues that everyone for miles around could smell the stench of death and expresses doubt that the 8-year-old son of a Nazi official could be unaware of what a Jew is (or whether he himself is one). He writes, "Note to the reader: There were no 8-year-old Jewish boys in Auschwitz -- the Nazis immediately gassed those not old enough to work. Additionally, the Auschwitz death camp was surrounded by electric fences, making any attempts to crawl in through a gap in the fence difficult and improbable."