Factual error: At the very start we see the Swastika flags hanging and they appear to be made of lightweight material. However, they were always made of heavier wool. (00:01:20)
Continuity mistake: When the children are shown the new home, the girl's face is one of joy. She's smiling a nice big smile that is hard to miss. In the next shot it is one of shock and has completely changed. (00:11:10)
Continuity mistake: When Bruno is playing in the courtyard, we see an officer with a dog stood in the centre of the gate. Camera cuts and he is now stood to the left of the gate. (00:19:30)
Continuity mistake: The landscape surrounding the prison camp changes from overgrown bushes to open plan. (00:39:10)
Continuity mistake: When Bruno is caught going into the front yard, he closes the gate. Camera cuts and it is open again. (00:48:10)
Factual error: At the end we see a soldier replacing the canister that the Zyklon B is kept in. However, he is not wearing an SS badge as all SS soldiers did. Zyklon B was only handled by members of the SS, as no other unit had authorisation to carry the sensitive stuff. (01:28:00)
Continuity mistake: When Pavel picks up the tire from the outhouse, it is a thin tyre with vertical lines, when Bruno is swinging on the tyre a few shots later, it is a thick tyre with lines both vertical and horizontal.
Factual error: At the end, When the Jews are in the gas chamber, Zyklon B is dropped in through a vent at the top. While this is correct and represents the method used by the SS, the results are not. In the film it is depicted that the victims are dead within minutes. While this is true to a degree, the actual effects took 15-20 minutes to actually kill. Yes some of the more infirm people will have died quickly but the entire chamber would not have died that quickly.
Continuity mistake: Bruno cuts his knee quite badly. However, the mark disappears in the following shots.
Factual error: The senior SS officer visiting the commandant (and later at the funeral) is wearing two oak leaves and a pip on his collar patches. This rank badge didn't exist. Two oak leaves (without a pip) were worn by an Oberführer and three oak leaves with a pip by a Gruppenführer.
Answer: Samuel knew the dangers of the camp and knew that trying to escape would result in death. He knows Bruno is likely to be allowed IN to the camp as he is a German and Germans are running the camp. Plus, if Shmuel did escape, where would he go? He's 8, on his own and alone in the woods.