Continuity mistake: In the first basketball scene, the coach says "Big game tomorrow." In the second basketball scene the next day, he says the game is next week.
Continuity mistake: Bud goes into the kitchen, and sees Betty when she has turned color. When she is seen from the back, her hair is still in black and white. When you see her colored face, her hair is brown. Once she is made up to be black and white again, her hair is once again without color.
Factual error: When the townspeople try to undo the changes brought about by David and Jennifer's presence, they declare that only certain recordings will be permitted, including those of Jack Jones. The action takes place in 1958. Jack Jones did not sign his first record contract until 1959.
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 ★
Considering that a couple of days in Pleasantville turned out to be just an hour in the real world, it's possible Jennifer could spend 3-4 years in uni and cone back with it being just a weekend in the real world. David could just make up something in that period she's gone.
Actually if a couple of days is just an hour than 3-4 years is more than 2 weeks.
lionhead