When Neal is in the office of Sergei, the portrait on the wall displays Tsar Nikolai II., the last monarch of Russia.
At the engagement party, Sergei tells Peter that he had hoped to meet his wife. Peter tells him that she had come down with the Flu. Elizabeth came down with the flu at the end of the previous episode.
When Peter shows the Peter Nevins bio it says that Peter Nevins was born June 12, 1969. Tim Dekays birthday is actually on June 12 but in 1963 not 1969.