The cover art for this battle is the first one to have the rappers in front of the "VS", instead of behind it.
During J. R. R. Tolkien's title card, the version of him closest to the camera is invisible for half of the sequence. Upon his sudden appearance, he can be seen taking a ring off his finger. This is a reference to the One Ring, the central plot element of The Lord of the Rings series, which has the power to endow the wearer with invisibility.
Jon Snow can be seen on his back in the background during the line, "Your bad guys die and your good guys survive!", but disappears during the line, "Ditch the Goonie, and cast a couple boobies!", before reappearing during the line, "Your hobbit-hole heroes can't handle my throne!"
Ceciley Jenkins' name is misspelled in the credits of the Behind the Scenes video as "Cecily Jenkins".
Multiple candle flames are seen bugging out in the Great Hall. Most noticeable during the line, "We can tell what's gonna happen by page and age five!", the left candle is unaffected, while both the middle and right flames have a rendering bug.
J. R. R. Tolkien vs George R. R. Martin - Behind the Scenes of Epic Rap Battles of History
J. R. R. Tolkien vs George R. R. Martin - Behind the Scenes of Epic Rap Battles of History pt. 2