I had noticed this for awhile. Towards the end of the movie when Marty returns to 1985, and the DeLorean is hit by the train, no one comes over to check out the wreak. You notice their are people stopped at the railroad tracks, yet no comes over to see if Marty is okay. Even after Marty picks up Jennifer, there is still no one checking the damage, not even a police officer. You would think after that, someone would have to see if everything is okay. Also when Doc returns with a time machine train, no one around is surprised to see a train appear out of nowhere.

Still a great movie.