Hugh Laurie directed some scenes when Ben Elton had to go to hospital for the birth of his children. Elton and his wife had been undergoing IVF treatment.
About 34 minutes into the film, there is a scene in a restaurant. In one shot, there is a waitress at the table, and another one setting down plates at a table in the background. The camera cuts away for less than two seconds upon th arrival of a character, then cuts back, but with both waitress prematurely gone.
In the scene where Lucy catches Sam working at his laptop in the middle of the night, his shirt changes from a t-shirt in one shot, to a sweater in the next.