Dr. Stables was your average doctor. He was as skilled as any other doctor, yet, unlike most, he believed in superstitions and urban legends. Most ponies would always expect a doctor to be steadfast and skeptical about these kinds of things, however he isn’t like most doctors. Believing in what seemed to be something most ponies would dismiss as 'just my imagination' or 'i'm just seeing things'. Nevertheless, Stables follows the rules bound by superstitions...
An encounter at the elevator would show just that.