"Dave Doggy Day" looks at Charlotte, and says "thought you was a St Trinians.....".
Clara Paget, who played Charlotte was in the movie St Trinian's 2: The Legend of Fritton's Gold (2009).
John Barnaby is Tom's cousin in the show.
When Inspector Barnaby hears a knock on the door of his new house he says "The Robinsons have moved". This is a reference to Samantha Bond playing Mrs Robinson in The Adventure of the Cheap Flat (1990).
First appearance of Sykes the dog who was previously known as Harvey in the Thinkbox advert. Sykes was a rescue dog.