At 16:51 when Alaric says to Isobel in a flashback "You're like Mulder, except hotter and a girl" he's referencing Fox Mulder in the X Files.
When Elena calls Isobel from the cell phone, Isobel's number is listed as (919) 399-2507. The 919 area code is associated with the Raleigh, North Carolina area.
Isobel's driver's license lists her address as 729 Oak Park Drive, Winston-Salem, NC 27104. Her date of birth is listed as October 17, 1975, and her height is 5'4''.
Paul Wesley and Melinda Clarke previously appeared in the same episode of The O.C. (2003) titled The Outsider (2003).
The episode title is also the title of a 1992 legal drama.