Trivia: In the courtroom scene, all the people that have turned to color have to sit on the upper level. This is reminiscent of "To Kill a Mockingbird" (1963) where, in a similarly-built southern courthouse in the 1930's, all the "colored people" (African Americans) were relegated to the upper level.
Trivia: When the TV technician is talking to the children through the TV, he is sitting in front of a test card with a picture of an Indian. The Indian's expression changes each time we see it (mentioned on the DVD director's commentary).
Trivia: When the mayor is talking in the bowling alley, you can see the projection of the score sheet. There is not a single open frame; everyone bowled a strike or spare every time.
Answer: We don't see much of the "real world" after David returns other than his conversation with his mother. I am sure in time she would have been worried but there seem to be many unanswered questions which might make it not so simple.
Lummie