The outside establishing shot of Spence's subway station shows it to be the Steinway Street G/R/V stop. However, the scenes inside of Spence in his token booth read "Queens Plaza" which is two stops away.
In the last scene, Arthur walks through the turnstile without paying. The turnstile would not move if token or metro card is not inserted. The turnstiles do not seem to have any slot to insert token or swipe metro card. The slot would be located on top of turnstile.
The character played by actor Michael Lowry introduces himself to Doug as "Mike Haller". He later introduces himself to Carrie once again as "Mike Haller". This wording is confirmed through the closed captions of the episode. However, in the closing credits, the character is listed (with an incorrect last name) as "Mike Ross", and his wife is listed as "Debi Ross".