During Stewart and Sir Curtis' meeting in the cable car in Switzerland, the bank note in Stewart's hand mysteriously disappears, then suddenly reappears later.
Seretse and Sullivan meet on a ski lift yet neither wears any cold weather clothing. just thin lounge suits.
The number plate on the Spanish policeman's motor bike is clearly stencilled and held on with tape.
When Sullivan is scuba diving towards the end he appears not to be breathing since no bubbles are seen.
Although they are in Spain, Stewart and Annabelle are driving out to the villain's house in Stewart's British car (with the steering wheel on the right). Not only did they not have the time to ship it - they only just flew over - but they also had no reason to do so, when they just could've rented a local car.