The story is heterodiegetic, in that the narrator is not directly involved in the story, which allows for an impartial view of the two characters, though it is also limited in only being able to follow the female protagonist's thoughts. This works well with the idea of Lenny as an avatar for addiction; his behavior is erratic and unpredictable, which would not be possible if the narrator were able to describe what he was thinking or feeling at any given moment. From a strictly aesthetic standpoint, the story would not operate as well as a homodiegetic piece, from the point of view of the woman or Lenny, because it would detract from their relationship and from the powerful descriptions given throughout. Were the female protagonist the narrator, the reader would have a hard time believing she were actively thinking and describing everything with the same intensity that we see here; even a creative writing teacher wouldn't go around describing the afternoon as "absinthe yellow and almond, burnt orange and chrysanthemum," with the sky filled by "a litany of kites" (93). Similarly, Lenny's narration of the story would become grating and hard-boiled, like a James Cain novel, very pulpy and not attractive to the same audiences that "Tall Tales" is.
Ultimately, "Tall Tales from the Mekong Delta" is, to me, a parable about the perils of addiction and its inexplicable power over an individual. The protagonist gives no real reason for following Lenny as she does, and every time she stops to think about her actions he tells her "You want to." He coerces her into doing these things, just as a formerly addictive habit still lurks in the back of one's mind. The unfortunate thing for the protagonist is she is unable to get away. She can't fight back the encroaching addiction, and at the story's end it finally overwhelms her as an "infected blue enormity [...] that knows you and where you live and [is] never going to forget" (107).