In the season 1 episode in which we first learn that Carter comes from a wealthy family, Carter's horse is described as a white Icelandic pony named Marigold. In this episode, at the Carter home, there is a portrait of Carter on a dark horse, described by the butler as "Marigold . . . his thoroughbred."
In the last scene just after Dr. Ross kisses Carol Hathaway the camera pans across the back window of the car Dr. Ross is going to leave in. As the camera pans you can very clearly see a reflection of some of the lighting equipment in the rear window, including a light and a scrim.