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.skeffderry
Plot hole: Perhaps the biggest plot hole in the movie is centered about the reappearance of the Owsla officer Holly. Even if the warren was destroyed right after Hazel's band had departed, Holly would not have caught up with them right before the new warren at Watership Down - even with the delay at Cowslip's warren - with the additional detour in Efrafa, considering that acquiring the amount of information he got from its organization would take more than just one or two days. In addition, Richard Adam's novel, on which this movie is based, features the location of Efrafa some distance away from the down, nowhere between it and the Sandlefort warren (Hazel's and Fiver's home). In fact, Holly went to Efrafa (along with a missionary group of Hazel's band) some time after they had settled down in the new warren.