Continuity mistake: After their long drive into the country, Robby and Ray begin arguing at the side of the road. In one shot as Robbie waves his arms, Robbie's blue boxers and pants are on so only the boxer's red waistband is seen. In the next shot, as Robbie still waves his arms, both the pants and boxers are pulled higher up, so now only a bit of the blue boxers are seen. (00:49:20)
Other mistake: When Dakota Fanning and Tom Cruise are in the house being searched by the alien probe, they use a mirror to shield themselves. We can see a diverging beam of light coming off of the probe, and therefore we should be able to see a related beam coming off of the mirror, widening even further. No second beam is visible.
Continuity mistake: When Ray is taking the van he's having a heated exchange with Manny, and Robbie's window is closed. However, just as Ray anxiously speeds away Robbie's window is wide open, for the dramatic close-up on Robbie's side view mirror, showing Manny's vaporizing demise, and when Robbie ducks his window is closed again. (00:31:10)Super Grover
Continuity mistake: When they leave Mary Ann's house in the minivan, Ray has Rachel in his arms, and the pink cord on Rachel's sweater disappears between shots. It's hanging on her arm, under Ray's chin, the first time he tells his son to get in the van, but it's not there the second time, and it's back on the third. (00:46:00)
Continuity mistake: In the van, when Ray says to Manny "Get in, or you're gonna die," the next shot shows Rachel's face with tears in her eyes saying "What do you mean?" with a very distressed look. In next shot from the left side of the van, you can see Rachel on the right side of the screen with a different expression on her face, looking more calm, yet, in the next shot the look on her face is distressed with the look of crying again. (00:31:00)
Continuity mistake: After Ray walks out of Mary Ann's destroyed house, he sees Max on the airplane wreckage. In the first shot Max's body faces out, towards Ray, as he drags the food locker, but in the next overhead shot Max's body faces the seats. His position and things on the plane also differ. (00:42:40)Super Grover
Factual error: The minivan that Ray drives is shown several times with its rear-most side window rolled all the way down. No such ability exists on any year/model of Chrysler-built minivan. They are either fixed (non-opening) or hinged at their forward edge to open like a 'flap' at the rear edge. The glass isn't broken, as it appears/reappears depending on the scene, and no such customization is possible as such a large window has no place to go down to due to the wheel well location directly below. The windows were obviously removed so the camera could move through the glass without having to use digital effects to go through the window, but in doing so, they created an obvious mistake.johnrosa
Continuity mistake: Ray places the box of groceries down on the island counter in Mary Ann's kitchen. In the following shots the box (and goods inside), ceramic pitcher with utensils, tray of napkins, peanut butter, bread and bag, repeatedly, and very noticeably, change positions. (00:35:50)Super Grover
Continuity mistake: As the tripod is attempting to have Ray sucked up, the soldier begins pulling Ray's arm down, trying to free him while he himself is being raised in the air. In the following shots, Ray's rescue is shown from three different angles, and each angle is distinctly different from the others. (01:40:00)Super Grover
Continuity mistake: Just before the first alien tripod breaks free from the ground and cracks are appearing in the street, the front of the church cracks, and rocks away from its second half. In that shot, in the view from behind Ray, he places his right foot on the curb, while his left foot is on the road. In the next shot facing Ray, both his feet are on the curb.
Continuity mistake: When Ogilvy shouts Ray's name half a dozen times, Ray runs to him to quiet him down. The broken cellar window behind Ogilvy has shards of glass and red roots growing on it. Then in the next exterior shot, the shards of bloody glass are different size and shape, and the roots differ as well. (01:29:35)Super Grover
Continuity mistake: In Ogilvy's cellar, in the close-up of Ray's hand, he holds it up to the red mist blowing through the two broken windows. In the next shot however, as Ray looks at his hand and realizes it's blood, the right window is suddenly blocked with a broken shutter and two pieces of wood. (01:29:15)Super Grover