Russell's (Johnny Vegas) earring disappears in a close-up when he approaches the food store at the start of zombie story segment of the film. It then reappears in the next shot.
In the first tale Paul enters the barn during daylight, then exits and it's night time.
Miki eats a from a large bag of frazzles crisps, This is a multipack bag which would contain 8 smaller bags and as such you wouldn't be able to eat straight out of the bag.