When Madeline and Helen meet in Madeline's dressing room, they kiss one another on the cheek. Madeline leaves a large bright red lip print on Helen's upper cheek. In the next shot, the print has moved down toward her chin area.
When Ernest starts to bolt with the potion, Lisle says "Tom, Dick, Harry, get the potion from him!" He picks up the dagger she stabbed him with. As he does, you see her reflection on the glass table. Her lips do not move when she says those words.
When Madeline is given the card with address of Lisle Von Rhoman on it, she tears it down the middle into two, and the two pieces she tears are torn neatly and straight down the middle. Yet later, when Madeline takes the two pieces of the card from her bag, they are torn much differently, and aren't torn straight and neatly.
When Ernest runs away from Lisle, after he nearly drinks the live-forever potion, he runs down a hallway and commences to open a door with a doorknob on the left side of the door. It then cuts to the other side of the door, of Ernest walking through the door (into the party), and now the doorknob is also on the left side of the door, yet is should be on the right side.
Seven years pass and we see Helen with her cats being evicted. Another seven years pass and we see Helen at her book signing party. However when Madeline catches up with Helen at the party Madeline says "twelve years."
When Ernest falls from the Castle, he hits the glass face-down, but when he is shown from below, his back strikes the glass. (Due to a scene in which he sinks to the bottom of the pool, retrieves the unharmed bottle of potion, and then swims up which was cut due to the change in the ending, ending the involvement of the potion in the story.)
When Ernest runs through ER looking for a doctor a short scene shows a CPR in action. On the ECG monitor a flat line can be observed, nonetheless the doctors try to revive the patient with an electric defibrillator. ECG flat line cannot be treated by defibrillation.
Helen has had a hole blown through her stomach by the time the "shovel fight" has begun. As Ernest leaves the scene, you see the shadows of the women fighting, only now the hole is in Madeleine's shadow, not Helen's.
Lisle (the first name of the von Rhuman character) is supposed to be the German-Austrian shortened nick-name version of Elisabeth. It is mispelled in the credits and should be: Liesl, as in the character from The Sound of Music.