Revealing mistake: During the scene when Audrey is having a nightmare about eating too much while on vacation, the nightmare ends with her inflating like a balloon from all the food. Her blouse splits open and down the middle, where the buttons have broken, the dark balloon used for the effect is visible. (00:16:35)
Continuity mistake: When the Griswalds are leaving the hotel in London they get in the hire car. When Clarke realises that the steering wheel is on the other side he gets out. When Ellen gets out she leaves her door open but when Clarke goes to get in the door is closed. (00:24:20)
Answer: The answer could be any of those suggestions. It could also very well be a movie mistake. It's not uncommon for character names to be misspelled, either on some document or in the cast credits.
raywest ★