When Karel meets Jamilla's mother for the first time, there is a moving shadow of the boom microphone on the pillar above and behind them.
A bus lists its destination as "Prague" A local bus would have used the Czech spelling of "Praha"
Heydrich was ambushed in the city of Prague, not on a country road. His travel plans were also no secret: despite Hitler's admonitions Heydrich always took the same route when traveling in the city, believing the the people were too cowed to dare attack him.
Given his girth and venality, the character of Himmler seems to have been based more on Hermann Goerring than Heinrich Himmler. Himmler had a rather slight build.