In the final scenes with Enrique on the construction site, the foreman is seen watching Enrique. In a medium shot, he is carrying a rule or spirit level in his left hand as he looks at Enrique. In the next shot, with Enrique in the foreground, the foreman is empty handed.
The plane that taxis up to the airport building is a DC-10, but the plane seen lifting off towards Chicago is a 747.
Whe Rosa and Enrique go through the tunnel, it is high enough for them to crawl on hands and knees, yet they crawl through on their stomaches.