Continuity mistake: The mask that is removed from Leo has 3 parts - a face mask which is held onto Leo's head, with a 2 piece hinged cage that locks in the back. In the flashback, where they show Leo being put in the mask, it is only 2 pieces. The face part is fused to the hinged cage section.
Continuity mistake: When the guards come to take Elizabeth away in the beginning, before she is queen, Lord Dudley has his back to the camera and is saying goodbye to her. You can distinctly see the clasp of a necklace on the back of his neck, but in the next few shots, there's nothing there.
Continuity mistake: When Shane first gets into Studio 54, he is told to take his shirt off. He pulls it over the top of his head. Then he walks in holding it and even though he never unbuttons it, it is somehow unbuttoned when he puts it on again.