Near the end of the episode, when Detective Murdoch is discussing the practical application of physics to hanging, one of the formulae on the blackboard lists acceleration from the drop as 30 feet per second squared. The correct value is 32 feet per second squared.
In the final scene, the doctor is listening to a recording of Claude Debussy's "Clair de lune". While Debussy started writing the piece in 1890, it wasn't published until 1905. He made recordings of the piece on piano roll in the early 20th century, at least a decade after the period of time in which this episode was supposed to have taken place.