Plot hole: After Superman has reversed time the Hoover Dam reverts to its previous undamaged state as it should, but Jimmy Olsen should then have been replaced back on the dam. Instead he interrupts the potential kiss between Lois and Superman and complains of being abandoned by Superman in the desert.
skeffderryPlot hole: When there is a big explosion at a plant and Superman flies in to save the day, all he does to stop the explosions is pull down the toggle of a huge switch situated on the wall; if this is all that was needed to stop the explosions, then why didn't one of the workers do it, and save Superman the trouble of flying all the way out there to do something which one of the workers could have done easily.
Answer: Just to clarify: Superman didn't spin the Earth backwards. We just see the world turning backwards when he went back in time. Of course this doesn't answer your question and it shows how difficult it is to write a good time travel story that doesn't leave the audience thinking of better ways to solve problems.
I guess the way they wrote it, Superman got to be the hero and also get the girl, not really too bad of an outcome.
briggs