Continuity mistake: When William takes Anna back to his flat, after the orange juice incident. His shirt is stained, she comes into the flat and changes. Then she leaves. When she returns to get her books, his shirt is still stained but after she kisses him the stain is gone. An impressive kiss...
Revealing mistake: In the scene where they are all having a farewell dinner at Tony's restaurant. At the end of the meal they are all scattered around the restaurant, the camera is on Bella and Honey and in the background, outside the restaurant, 4 extras walk past, 3 at the front and one behind. The next shot is at the window where Max and William are sat, again the 4 extras walk past in exactly the same order and positions. They are the same people because one of them has a pink top on and you see that twice.
Continuity mistake: After William leaves the movie set, in the next shot he goes back to the book shop. Seen through the window is the table with the books and globes. Then when Anna is standing near the window, we see that there are completely different kinds of books on the top shelf now.
Revealing mistake: In the scene where Will and his friends are driving to catch Anna at the press conference, Spike jumps out of the back of the car to halt traffic and let their car through. When he closes the back door, the sound effect of a slamming door is loud, but the door doesn't shut - you can see it bounce back up.
Continuity mistake: When William initially walks into his bookstore after he takes the mail from Martin, on the bookcase he approaches to his right we see close-up some of the books on three shelves, one of which says 'Siberia', and also the two small posters, the bottom says 'Mukiwa' and the top says 'Lonely Planet', tacked to the side of this bookcase. When Anna browses that same bookcase, she looks at the book 'My Turkish Delights'. The books that are on the shelves of the bookcase, and only the top poster that is tacked to the side are now completely different.