When Steed and Gale are conversing at Victor Gibb's firm, their voices are drowned out by a loud cough from off screen. It is actor Geoffrey Alexander clearing his throat before entering the scene and saying his first line.
In several scenes, the door to Lord Teale's office refuses to stay closed after people enter through it.
When John Wrightson enters the Wrightson house and sees Ms. Gale for the first time, there is a close-up shot of his face. His expression starts as a smile at meeting an attractive woman, but changes to annoyance when he realizes she is asking questions about his father's bequest. The boom mic is briefly visible during the close-up.