Factual error: In the scene where a boy runs on the streets of Moscow, he passes by the famous Moscow landmarks: St Basil's cathedral, Moscow State University, Big Stone Bridge etc. In reality it would have taken him a good four or five hour run to do that.
Factual error: As the plane hits the water, Chuck falls backward, toward the rear of the plane. This violates the physical law of momentum. He actually would have continued traveling forward toward the incoming water.
Continuity mistake: When Chuck first goes over and sees the cave, it changes the camera angle and the sunlight is significantly dimmer and more orange, indicating a sunset.
Continuity mistake: The scene where Tom Hanks goes inside the cave for the first time during the storm, he has the flashlight from the dead pilot with him. The flashlight is in front of him when he sits down, but you can see shadows on the rock wall beside him in the wrong places.
Continuity mistake: Near the end of the movie Chuck and Kelly are standing in the street in the pouring rain. Chuck leads her to the passenger door of his car and she gets in, still dripping wet from being in the rain. Then Chuck goes around to the driver's side and gets in the car, but amazingly he is not dripping like Kelly; his face and hair are somewhat dry for someone just coming in out of a downpour. (Tom Hanks must have a problem with doing his lines with his face wet because, ironically, he did the same thing in a scene in Forrest Gump after jumping off his boat to meet Lt. Dan.)
Continuity mistake: When Chuck first lands on the island he gets up and looks around.. he starts to walk down the beach and after a little while he looks back and sees his own footprints. He turns back around and the camera cuts to a wider shot.. you can clearly see his footprints get washed away by the waves. The camera zooms in as he picks up a FedEx box and zooms back out as he turns around again and his original footprints are there.
Other mistake: When Tom Hanks cuts his hand and loses his temper, he picks up the volleyball with a bloody hand and throws it. When he picks it up, you can see that his fingers are spread. When you see the handprint that he makes "Wilson" with, you can see that the fingerprints are together and parallel.
Continuity mistake: The final sequence of the film has a whole load of stuff different. Just before Chuck walks into the crossroad, we see there's a solid double yellow line on the main road, a dirt track to one side, and another road on the other side - that one has one solid & one dashed line on it. It cuts to a wider shot, and the dashed line has suddenly become solid, the Texas state sign has moved closer to the stop sign, and a big shadow (of a telegraph pole or similar) has appeared next to the stop sign. There's then another cut looking down the adjoining road - Tom Hanks' shadow's done a complete 180, the shadow of the telegraph pole's disappeared, the line's gone dashed again, and the Texas sign's moved away. Basically, in one 20 second clip at least 4 things change significantly - they used two very similar, but not identical junctions, for no good reason. A veritable spot the difference competition!
Revealing mistake: When Chuck is writing on the rock waiting for the wind to change direction, you can see that when the wind changes direction the trees behind him are duplicates.
Continuity mistake: After Chuck Nolan (Tom Hanks) injures his hand and throws the volleyball "Wilson", in the following scenes pay close attention to the box that the volleyball is in. One scene the box has a visible tear along the top rim of the box; then, before Tom Hanks opens the box to remove "Wilson" another box appears not torn.
Continuity mistake: Throughout the film, Tom Hanks has a dark lump above one of his eyebrows. This seems to come and go from scene to scene.
Revealing mistake: The container that breaks the net is made up to be an AMJ container, with the 45 degree angle on the upper corner to fit the contour of the plane. However, as the camera zooms back out to show Tom Hanks, you can see that the side of the container towards the center of the plane is entirely clear, with packages visible. If it was a real AMJ, this side should have a white or purple curtain covering almost the entire side. That can is a prop.
Character mistake: Towards the end of the film, when Helen Hunt runs after Tom Hanks, she definitely does shout "Jack! Jack!" It's not Chuck by any stretch of the imagination.
Continuity mistake: When Chuck is attempting to start a fire his hands are so badly scratched/blistered that he ties a piece of fabric around one of them. Once he has started the fire and is doing his little dance on the beach his hands face the camera and there is not a mark on them.
Continuity mistake: When we first see Chuck washed up on the island in daylight, as he gains consciousness and awakens inside the life raft, he is clean shaven. A moment later when he is walking down the beach collecting the FedEx boxes, he has grown a full day's worth of beard stubble.
Revealing mistake: As Tom Hanks escapes from the sinking aircraft, it shows him still underwater, looking back and the plane breaking apart. It shows an AKE-shaped container (which fits the contour of the bottom of the aircraft) which has no markings at all, it appears to be just a computer generated solid with no color.
Factual error: When the FedEx packages wash up on the beach, all the contents are completely dry. Even the birthday card from the grandma is completely legible. FedEx does have waterproof packaging, I am sure, but those appear to be just regular boxes.