At around 9 min. mark when the first B-17 is rolling out for the bombing raid over Berlin, the national insignia (star and bars) is seen on the right wing and the air group letter "D" on the left. This is wrong (reversed). The national insignia is always on the right side (seen from the top or from below). In all other scenes this was shown correctly.
During scenes depicting Stalag Luft III, a Dodge WC54 ambulance in plain green colours, can be seen in the background. This is an American vehicle and would have had no business being located in this camp at the time of the war this episode portrays.
The alto sax player appears to be using a Rovner ligature, which began production in the 1980's.
On the bombing run the pilot declares they are 30 seconds away from the target then hands over control to the bombardier, who immediately declares bombs away, far less than 30 seconds later.
In the beginning buck says flak is firing and that that must mean they are going to bomb Berlin, From rest of the episode you can see that course is going nowhere near Stallag III where they are stationed so they couldn't hear it.