Towards the end of the episode, Joan walks into the living room carrying a bowl of popcorn to find Holmes sitting in the dark. She remarks that she didn't know he was in there, and that she was going to watch a football game. Holmes comments, quizzically, "But it's Thursday". CBS had delayed the start of this, and last year's season of Elementary in order to present football games.
The three "doppelgängers" are being murdered/pursued are all played by the same actor, Brendan Bradley.