In episode 4, "Defiance", of this mini-series, Pug Henry (Robert Mitchum) and Pamela Tudsbury (Victoria Tennent) are in a scene riding on the top of one of London's double-decker buses. The camera is at seat level looking up at their faces and buildings are going by as the bus moves. One of the buildings has flags from many countries flying from it and one of them is the Maple Leaf flag of Canada. Unfortunately, this flag wasn't created and approved as the Canadian national flag until the 1970's and the mini-series is shot in 1939-1941.