During the final shot, of the two time machines flying through the vortex, the stick upon which the Dalek time machine is mounted is clearly visible.
The actor on the top of the Empire State building claiming to be from Alabama has a very poor imitation Texas accent.
When Vicki is about to whack the sailor on the head, the sound effect of the BONK comes significantly ahead of time.
As the Doctor reveals the Daleks are gaining on the TARDIS, a production crew member is visible in a gap in the wall of the TARDIS set behind him.
The Empire State building tour guide gets the building's height wrong: he says it is 1,473 ft instead of 1,454 ft.