When Christine Keeler is swearing an oath before giving evidence at the trial of Stephen Ward, she uses the standard phrase "I swear to tell the truth, the whole truth and nothing but the truth", but then she adds "so help me God" which is American wording that is not used in British courts.
The police inspector, Herbert, says of Ward, "He's a ponce. End of." The use of "end of" to mean "there's nothing more to be said" did not become current in British speech until the late 1990s; the story is set in 1963.