The story structure is similar to that of the Agatha Christie story "And Then There Were None" (people trapped on a remote island, prey to a killer in their midst). The name "Owen Island" is a nod to the absentee hosts in the novel, Mr and Mrs U.N. Owen (i.e. "unknown").
The episode's title; "Proteus" likely refers to the ancient Greek sea god of the same name. Proteus is said to represent the unpredictable and changeable nature of water; the god himself was often said to frequently change forms.