Mary Woodvine, who plays Mrs Cronk, is the daughter of John Woodvine who plays Doc Martin's father.
This episode marks the first appearance of Peter Cronk, played by Kurtis O'Brien. In season seven the character is played by Preston Nyman.
The troubled forester goes over all the members of the town and their quirks to Doc Martin, which is a way to remind the audience (in case they're tuning in late) of the show's characters.