In the dancing-lying-down scene, Gregory first appears lying to Susan's left (right as we see it). In the final shots of this scene, the positions are reversed and Gregory lies to Susan's right.
Toward the end, when Gregory and Susan are on their date at the park, the amount of daylight keeps changing back and forth multiple times.
Women did not in 1980 (and still do not now) outnumber men by 3 to 1 in Caracas (the capital of Venezuela), although it may be believed and then repeated by some of the young men in the movie merely to show how uneducated, naive, and gullible they are.
When the windows cleaners are outside the classroom, the younger one rises into sight in a bouncing motion as if the cradle he is in is being hoisted up. However, none of the ropes attached to the cradle are moving. It is obvious the actor is simulating this upward motion.
When the small girl tells Gregory that Dorothy would like to see him in room 9 at break time, after combing his hair, he proceeds to room 39 and there she is.