Mike, Carol and Bobby are seen leaving for the TV studio in Mike's blue convertible, but they return in Carol's station wagon.
The Kartoon King collects all the spoons before the Ice Cream Contest so the boys must eat with their mouths. The boys are then instructed to place their hands behind their backs. The next shot, a close-up of Bobby, shows his spoon next to his bowl.
When Mike, Carol and Bobby are returning home, Carol mentioned, "hey, that's strange, looks like everybody is out of the house", presumably because there are no lights on in the house. When they get inside, the house is dark, as if it is night. However, if you look at the sky as the car is turning in the driveway, it appears to still be daytime. Even if the lights were on, one would not notice that during daylight.
When eating the ice cream there are obvious differences with the messes on the kids faces that could be overlooked given the content of the plot; however, there is one mistake with the ice cream that can not be excused (other than bad editing). When the Kartoon King is squirting the whipped cream on the third kid's bowl a little of it misses and a tiny bit can be seen on the side of the bowl. Then even before the kids get the signal to eat it's shown in another shot to be gone. Another thing the third kid sets something down on the table on the right side of the bowl that keeps appearing and disappearing.