Revealing mistake: In the swimming pool scene, when David is sitting at the bottom of the pool, you can clearly see a scab on one of his knees. (00:43:00)
Continuity mistake: After the pool incident when David is writing letters. Monica is looking over the letters that David has written. There's a point where you can see that she's still holding at least 2-3 sheets of paper but when the camera shifts back to the writing there's only one in her hand. There should be more than one paper in her hand. And when viewed from behind her back the sheets are neatly lying on top of each other, when seen from the front, the sheets are tilted. (00:46:43)
Revealing mistake: When the robots start to scavange the pile of robot rubble the moon balloon comes over. One of the robots shouts, " Moon on the rise!". If you look carefully you can actually see the actors' real bottom lip behind a metal robot jaw that isn't meant to have any flesh or skin. (00:58:15)
Continuity mistake: The poem displayed in Dr. Know's booth and the one on the door in Manhattan are slightly different. Dr. Know displays the line "waters and the wild" whereas the poem on the door read "waters of the wild." (01:26:30 - 01:34:10)
Audio problem: When Monica runs back upstairs to see what David did to her perfume bottle, the sounds of the footsteps on the stairs don't sync up with the steps we see her taking. (00:24:40)
Continuity mistake: In the scene where they are operating on David after he ate the spinach, if you look closely, you'll see that the little electronic gadget that pops out of David's torso comes out three different times. (00:35:50)
Revealing mistake: When Monica is reading to Martin, her cryogenically frozen son, you can see the body move. (00:08:00)
Plot hole: When Martin decides to antagonize David by eating spinach, he eats it from his plate. When they both eat the spinach frantically, they each eat out of a large bowl. Where did the second large bowl come from, and why would there even be a second one if they only need enough for three people? (00:34:55)
Continuity mistake: When Monica first meets David, David walks out onto the carpeted floor and takes a step down to the wood tiled floor. He taps his feet on the wood tiled floor and then steps back up to the carpeted floor. He taps his feet again and turns around to face Monica. This is just before he tells her, "I like your floor." The mistake here is that Monica was pulled from the carpeted floor to the wood tiled floor before David walked in. So, David should not have had to turn around to face her because she would have been in front of him ... not behind him. (00:10:30)
Continuity mistake: When the doctor takes out the chip filled with spinach, the amount of food on it differs between shots.
Factual error: At the end of the movie when David jumps into to the water in downtown Manhattan, he lands in Coney Island. Coney Island is in Brooklyn, a long way from Manhattan.
Plot hole: Hair does not contain DNA so the boy's mother could not be recreated from just a snipping of hair. The hair follicle contains DNA but that would only be present if the hair had been ripped out. The robot bear that gives David the hair didn't really have a chance to get any hair as he left with David early on in the film and they never returned. Added to that even if he did have the opportunity, he wouldn't have thought about getting extra hair. They only find out about the DNA cloning at the very end of the film when the mother had passed away a long time ago.
Audio problem: When Henry asks David why he was going to cut Monica's hair, the sound is out of sync with his mouth. (00:39:30)
Continuity mistake: When the robot catcher nets in the stray robots including David they go in the cage of the moon balloon, where David is struggling to hold on to Teddy as the balloon rises into the air. Teddy says "l'll break David" and at that point Teddy slips through Davids fingers and falls to the forest floor. Teddy then immediately runs to the top of the hill where the balloon he just fell from has already sunk well behind that hill only just seconds after falling from it. The balloon has moved far too quickly. (01:02:50)
Continuity mistake: When the boys are swimming, you can see one boy get out of the pool twice. (00:41:15)
Continuity mistake: When we see the chef mecha in the cage, he has a hat on, and it is a permanent part of his head. But earlier when he was searching for an eye in the pile of stuff, he doesn't even have it on. (00:58:00 - 01:27:20)
Continuity mistake: In the scene where Martin is convincing David to go cut a lock of Monica's hair, watch David's top pajama button. When you see David head on, it's unbuttoned, but when seen from the side, it's buttoned. (00:39:13)
Continuity mistake: When David goes to cut a little hair from Monica about half an hour into the movie she is facing left, shot of David, back to Monica, now she is facing right. (00:38:25)
Continuity mistake: They show David staring at the silver dancers dangling above his bed in which he sees his reflection. Next shot shows him down too low to be seeing his reflection. Also, there is a sound of a wind chime, however the silver dancers are not touching to make the sound.
Continuity mistake: When David smashes his robot, the first blast turns the head to the right, but half a second later it's turned to the left.
Chosen answer: It was dangerous for Mecha to go there; he was afraid for David's safety.
David R Turner