After Humbert slips on the bananas in the hotel room and tackles Lolita on the bed, her lipstick changes three or four times
The movie should end in 1952, not 1950. Like the novel, the year is 1947 when Humbert meets Lolita, but the book states that both cross country trips and the time they spend at Beardsley amounts to about 2 years. The film has the same "3 years later" time jump as the novel, but there's no way from summer of 1947 to fall of 1950 could they have spent a year traveling the country, stayed in Beardsley for most of the school year, had another few months on a second cross country trip, and then have Humbert searching for Lolita for 3 years.
When Humbert is in a second meeting with Miss Pratt and Reverend Rigger, he puts down the cake he is eating twice without picking it up in between.
The blood disappears from Clare Quilty's face when he falls to the floor.
When Humbert sits down to remove Dolores' shoes (in the hotel room) she offers up her right leg in the wide shot. However, when the shot moves in close you see him holding her left foot and proceeds to remove her shoe.
When Quilty plays the concerto's opening theme on the piano, his hands are ascending, but the music is descending. However, the piano continues to play when he leaves it, indicating that it is in fact a player piano, and he was not playing the piece at all.
In the jawbreaker scene, the jawbreaker is at first bright yellow, then in the next shot, is white. However, jawbreakers often change color as they are sucked, so it is conceivable that the yellow layer had melted off, revealing the white underneath.
Charlotte threatens to "ground" Lolita. Though the term was known to airmen it would not assume its current familiar meaning for many years.
Lolita and a schoolmate leave each other with "See you later, alligator / In a while, crocodile," an exchange about a decade too early.
When Lolita looks through the stacks of $100 bills Humbert has just given her, they are clearly modern notes with design elements and signatures of the 1990s, not the earlier versions that would have been in circulation circa 1950.
The film set around 1947 features a 'Magic Fingers' (brand) vibrating bed. However, this was a 1958 invention by former salesman John Houghtaling.
A suspiciously modern water-tower is briefly visible behind Humbert during the car accident.
Reflected in the car window as the car rolls away.