When the Ice Cream Man's store is being trashed by the police, you see Ice Cream Man wading around in the spilled ice cream. Ice cream gets all over his shoes and his pant legs. Later on when he is outside, there is no ice cream glop on his shoes, and his pants are clean.
In the beginning sequence, the ice cream truck reads (on the back doors): "Watch Out For Children." Later in the movie, we see that Gregory has painted over the word "For" so that it now says: "Watch Out Children." But, at times, the word "FOR" is mysteriously back on the van, sometimes from one shot to the next.