Jock's quote "We're all doomed..." predates by several years the same words used as the catch-phrase of John Laurie as Private Frazer, another constitutionally pessimistic Scotsman, in Dad's Army, another 1960s comedy about World War 2.
When James Robertson Justice's character shouts at the Lageroffizier, it translates as "You can kiss my arse, you filthy Nazi!" Possibly, James Robertson Justice, who spoke fluent German, ad-libbed this, certain that the rest of the crew probably wouldn't understand it, most of the audience wouldn't and the censors undoubtedly wouldn't (or get the jokes).