This was Jon Finch's final television appearance before his death on December 28, 2012 at the age of 70.
The scene where the 3 detectives watch their guv'nor and her ex-lover talk and make deductions about his marital status and children simply by viewing him through a window is reminiscent of a conversation Sherlock Holmes and his brother Mycroft have in "The Greek Interpreter,"' in which they deduce that a man they see is a recently discharged soldier and a widower with more than one child.