Continuity mistake: Hogan gives a birthday party when the prisoners capture a German plane. When it is taking off, it is an English Lancaster bomber with a twin tail. As it is flying overhead, it is an American B-17 with a single tail. Finally as it is shown flying, it is a German FW-200 maritime bomber.
Other mistake: Klink has on his monocle, as usual. If you look closely, the monocle is a single lens, with no frame. From Episode 2 onward, the monocle has a frame and a gallery. Also, Klink wears it at an angle, not unlike the Penguin in the original Batman series, who also wore a monocle without a frame.