When Ralph receives the phone call from Lisa and leaves his chair, he knocks the table, rattling the chess pieces. However, Peter stops them from falling off the chess board and the chess clock remains in position. When Peter gets up to follow Ralph he doesn't knock the table at all, but as we cut to a long shot of Peter leaving the table there are no chess pieces at all on the board and the chess clock is on the floor.
Antonio Banderas' character runs past a public square where a man is sitting with luggage and a red jacket slung over the backpack, a second later Liam Neeson's character passes the same man who is now wearing the jacket but is in the same position.
Sitting on a bench in St. Pancras station at the end of the film we hear over the tannoy that the train to Cambridge is to depart from platform 7. Trains to Cambridge don't run from St. Pancras but from nearby Kings Cross.