A female audience member is clearly heard saying, "Don't fall down," when Ralph is trying to learn the Hucklebuck. Later, at the rink, possibly the same person is saying, "Steady... steady now," as Ralph is trying to bring over the coffee while on roller skates.
The edge of the apartment set on the left side of the screen can be briefly seen when Ralph first starts dancing and when he tells Alice that they are going to go roller skating.
Ralph asks the counterman for "a couple cups of coffee", but the man gives him three cups.
When speaking about her evening plans, Judy stumbles on her line, stuttering the words "bop contests".