Trivia: When Kevin arrives at New York Airport, the woman at the counter who tells him which city he's in is Ally Sheedy. This film was written and produced by John Hughes, who also directed her in the 1985 film "The Breakfast Club."
Trivia: In the scene where Kevin is first entering the Plaza, he stops to ask a man where he might find the lobby. The man Kevin stops is Donald Trump, owner of the Plaza.
Continuity mistake: When Kevin is running away from Harry and Marv he buys strings of pearl necklaces, and pulls them apart on an icy corner. When the bandits slip on them, there are more pearls there than Kevin dropped.
Continuity mistake: When Kevin is in the taxi going over the bridge, he is wearing gloves. But in the closer shot he is not wearing gloves. (00:19:30)
Continuity mistake: In the scene where Harry and Marv are at the skating rink, the front of Marv's hair is constantly changing from shot to shot. It's either poofy or pulled back due to the earmuffs he's wearing.
Continuity mistake: In the final scene, Kevin approaches the pigeon woman. She says "Merry Christmas" without any pigeons on her head. The long shot is taken, and she now has at least four pigeons are sitting on her head. A close-up is taken when Kevin approaches and reaches her hand, and again, pigeons have disappeared from her head. Impossible to have the pigeons flying on and off her head in the space of half a second.
Continuity mistake: Kevin is being served ice cream in his hotel room. A wide shot of the bed shows the food around it and the waiter scooping ice cream into a bowl. Look at the tall pink rose at the end of the bed, which towers out of its vase. In a couple of shots later, the rose suddenly becomes barely higher than the vase itself. (00:33:30)
Trivia: Right before the camera shows Kevin walk up to Mr. Duncan to pay for his things, it shows a man and his baby. The man is really Chris Columbus (the director of the movie) with his daughter (Eleanor Columbus) who later played Susan Bones in the first two Harry Potter movies.
Revealing mistake: Makeup is visible before the first brick hits Marv Merchants.
Chosen answer: Remember that Kevin didn't give his name, nor did the police ever see him. When he called, it was from a different address and he gave his name as "Murphy." There is no reason to think that Harry and Marv would tell the police about Kevin, since they would have to admit being outsmarted by a child and also admit to kidnapping, assault, battery, and a wide array of charges for what they tried to do to him. Even if he did testify, there is no reason to think his parents wouldn't know.
Greg Dwyer
And by the way Kevin knew nobody would believe him.
Not entirely correct - He rang the Police from the phone in his parents bedroom just before the spider scene.