As the boy (Boda) picks the lock to open the door where Jan is tied up, he dumps the contents of his pockets on to the floor outside the room. Once he gets the door open he immediately goes inside and releases Jan. Once Jan is released, he and the boy rush out of the room but the things are no longer on the floor.
The character of Reinhard Heydrich wears the collar tabs of an SS-Gruppenfuehrer (group leader, roughly lieutenant general), three oak leaves. As Reichsprotektor of Bohemia and Moravia his rank was higher, SS-Obergruppenfuehrer (higher group leader, roughly full general). The proper insignia for this rank in 1942 was three oak leaves with a single pip underneath.
After the German soldier shoots open the study door at Czaka's house, the door is opened yet there are no bullet holes, around the door handle or in the door or frame, even though there were at least 10 rounds fired by a machine gun.