When Tom & Barbara fly to Mexico, they leave on a plane with AMERICAN (airlines) on the rear of the plane. When they land, they arrive on a PAN AMERICAN plane.
Anton removes the knife from the vase twice between shots.
After using his first car at the airport, Romero switches to an 1941 Oldmobile 70 series with blackwall tires, but during this driving sequence the car turns into a 1941 Oldsmobile 90 series with whitewall tires.
The singers never move their left fingers on their guitar strings.
When The Falcon shows Hughes the painting after waking him up, the painting has a large noticeable crack across it from having been folded instead of rolled up. The erudite Falcon would have known how to handle a painting out of its frame to prevent such damage.