Legendary writer Robert Holmes, who had written for television drama since the early 1960s, had already died before the transmission of the episode.
When Bergerac mutters "So much for Conan Doyle" in the conversation about how the dog reacted, he is referring to the Sherlock Holmes story "Silver Blaze" in which the fact that a dog didn't bark during the night indicated that he was already familiar with an intruder. Writer Robert Holmes probably included this line as an oblique reference to his own surname.