Continuity mistake: As Drew Pearson is doing his news broadcast, the desk next to the microphone is clear. In the next frontal shot, two pencils have appeared next to the left of the microphone. (00:06:20)
Continuity mistake: As the spaceships runway platform emerges from the ship, there are hardly any trees behind the spacecraft; only a few behind the left side. In the next wideshot, there are plenty of trees behind the ship. (00:07:35)
Continuity mistake: When Gort emerges from the spaceship, we see all of the crowds run away in fear and panic. Yet in the very next shot the crowds are visible standing behind the ropes again. (00:10:05)
Continuity mistake: When Klaatu posing as Mr. Carpenter is sitting with the others at the table, Helen says "Well after all, he was shot.." and Klaatu holds his newspaper up in his hands. In the next shot he holds it down on the table. (00:26:10)
Continuity mistake: When Klaatu writes some notes on the blackboard, in order to help Professor Barnhardt, the handwriting of the words on the board changes between shots, most noticeably the 'T' on 'Try.' (00:35:00)
Continuity mistake: When Klatu goes to see the professor, there are several white notes tacked around the chalk board. In later shots some of the notes are gone. (00:39:25)
Continuity mistake: Klaatu introduces himself to the Professor for the first time by relaying some details of his stay at the hospital to verify who he is. Klaatu tells the Professor he was staying in room 309, but the early scenes at the hospital show him in room 306. (00:41:48)
Continuity mistake: The taxi Helen gets into changes in one shot as it drives down the highway, evident by the writing on the side, then back again when it parks outside her house. (01:07:35)
Continuity mistake: In the newspaper headlined 'Step up Hunt for Spaceman' the photo on the right shows Klatu and Gort on the hull of the ship. This shot is a still from the end of the film. (01:07:36)
Continuity mistake: In some shots, Gort the robot has air vents under the chin. In others there are no vents. (01:19:00)
Continuity mistake: During the news broadcast, the TV announcer is evenly lit. You can see this in the side view of him, as well as on the TV monitor that's next to him. Then, just after he says "there is no reasonable cause for alarm," the microphone in front of him is suddenly casting a big shadow on him.
Continuity mistake: Just after Klaatu gets shot, Gort is seen melting the clear glass/plastic/cement material he was encapsulated in. When Patricia Neal begins to approach the space ship, the camera shows Gort still melting the material with it almost down to his ankles by this time. The next shot shows Ms. Neal looking at him, but when the camera goes back to Gort, the cement he was encased in is suddenly back up around his waist. How did it get back up when moments before it was down around his ankles?
Continuity mistake: When the power goes out there is a scene where it shows all the cars not being able to work, although in the background there is a movie marquee with the lights on.
Continuity mistake: Patricia Neal is in flats as she runs across the field to give Gort the message. When Gort picks her up, she's in heels.
Continuity mistake: At the end when the spaceship is about to take off the people rush away from their chairs in fear of the launch. After the ship launches there are no chairs anywhere on the field, just the people.
Continuity mistake: After the power comes back on, a newspaper front page has Klaatu pictured with the president standing just outside the entrance to the saucer's dome, and Gort standing about five feet in front of Klaatu in the same place. But early in the film, Klaatu was on the ground with the president, and Gort never preceded Klaatu coming out of the saucer.
Answer: They said, how they handle their earth problems is no concern to them, it's only if they bring it to outer space and other worlds, they would take drastic measures to ensure that did not happen.