At the end of the film when Richard prepares to scatter the ashes of his father the wind is quite obviously blowing into his face. However CG ashes are blown into the opposite direction.
About 42 minutes in Pierce Brosnan and Salma Hayek get into a convertible Mustang that has a baby seat in the back. During their journey it disappears only to appear again when they arrive at their destination.
In the restaurant scene at the beginning, the capsule of the opened wine bottle changes during shots from completely exposing the lid to almost covering it. It looks like at least three different bottles have been used during shots.
When Olivia pulls up to the curb near the school in Richards Mustang there is a girl walking down the sidewalk wearing a red top that looks like the car startled her. When they get out of the car the girl is gone and instead further down the sidewalk in the direction she was heading is a woman and a young girl. This young girl is wearing a white top and a backpack.
When Richard first 'Skypes' Jake, we are looking at Jake in Richard's laptop screen and we see Jake walk off and the camera pans to follow him. Jake is using a laptop without anyone nearby to move his camera to track his movements.
After returning to LA, Pierce is in his garden talking, he takes off his scarf and at the end of the scene his scarf around his neck again.
The letter to Richard Haig at the end of the film is addressed to 170 Trinity Lane, Cambridge CB2 TTB.
There are barely a handful of buildings on Trinity Lane to come close to 170 (most aren't numbered anyway, just college names). Also, the postcode looks like it was incorrectly transcribed by the researcher - Trinity Lane postcodes are CB2 1T*
Whenever Richard has a phone call he holds his cellphone (HTC One) upside down.