Chuck Lorre's Vanity Cards simply stating "Uh-oh" was in reference to Donald Trump winning the 2016 Presidential Elections three days before the episode was broadcast.
Third time that Howard sits in Sheldon's spot, after The Apology Insufficiency (2010) and The Parking Spot Escalation (2012), although this is the first time that Sheldon is not around to see it.
Sheldon's inability in the opening scene to proceed until someone completes his Charge Fanfare shows that he still has a pathological need for closure, something Amy thought she had cured in The Closure Alternative (2013). By now, Amy must also be aware that Sheldon only faked being cured.
Raj mentions his sister being a lawyer, a reference to Priya, who was last seen in The Good Guy Fluctuation (2011) and last mentioned in The Recombination Hypothesis (2012).
This episode was taped on October 25, 2016.