You can see Flick's tongue come off the flagpole a couple of times.
As the teacher sings to herself while standing near the chalkboard (after a commercial break), the door to the "You'll Shoot Your Eye Out" set opens up by itself on the left side of the screen, briefly revealing the white interior.
There was a sound glitch during "Up On Santa's Lap" with one of the helpers, then with Matthew Broderick.
A store called Old Navy is shown in town in one scene. This is obvious product placement for the show's sponsor as Old Navy didn't exist until 1994.
A cameraman is seen standing in the street near the end of the Hanukkah song when everyone goes back inside the house.
During the Hanukkah song, when the others enter through the back door, scaffolding can be seen behind them.
The original story involved Ralphie going out in the back yard to take a shot at something and have his mishap, which would explain why the back door was left open. However, here he went out in the front yard to have his mishap, which meant the back door was open for no reason whatsoever (other than for the Bumpus hounds to come in).
One of the helpers singing the Higbee's song accidentally threw his present in the air, but recovered nicely.
It took Miss Shields two attempts to grab her feather at the end of her song.