Continuity mistake: Gimli is lying with his face under the water, after jumping off the Deeping Wall and landing on the Uruk-hai. In the close-up, the right arm that grabs Gimli's shoulder to help him out of the water is Legolas' right arm. Yet, in the wide shot, suddenly it is Aragorn helping Gimli to his feet, not Legolas. (01:11:10)
Continuity mistake: As Faramir holds the Horn of Gondor, the rope is attached to metal loops on the smaller half of the horn - without the mouthpiece. However, in FotR, when Boromir is hit with the third arrow and the Horn of Gondor is cloven in two, the rope is attached to the metal loops on the half with the long mouthpiece. (There are only two metal loops and they are permanently affixed.) (00:31:50)
Continuity mistake: Merry and Pippin were bound when taken by the Uruk-hai, and the bonds weren't cut until after they managed to escape during the fight. Yet, when the horse almost crashed down on Pippin, he had his arms spread out up near his face, not bound, even though they weren't cut until later. In the next shot, his hands are bound again. (00:31:15)
Other mistake: When Eomer is mounting his horse after giving Aragorn, Legolas and Gimli the two horses, you can see his sword falling out of its sheath. (00:35:00)
Continuity mistake: When the Uruk-hai stop to rest by Fangorn Forest, they drop Merry and Pippin right next to each other, yet Pippin then has to crawl some distance towards Merry so that he can speak to him. [On the Extended DVD, Peter Jackson says that parts of this scene were shot two years apart, and that in fact it was made up of shots for two distinct scenes. Either of these might explain this discontinuity in positioning.] (00:27:55)
Other mistake: Just as Gandalf and the Rohirrim are riding into the Uruk-hai and they clash, go slowly, frame by frame. Legolas will be on the right of the screen. Keep going frame by frame. You'll soon see a few pretty clear frames of Arwen with her sword, on her white horse. She's sitting to the right of Legolas. Her long hair is pulled back into a braid. She's wearing pink sleeves. She's the only one on the screen with that color, so you can't miss it (slow motion can be helpful but is unnecessary). The official reason for editing out Arwen (given on the DVD extras) was that during filming Peter Jackson intentionally leaked an image of Arwen at Helm's Deep online to gauge fan reactions, then backpedalled over her presence after overwhelmingly negative fan reactions. (01:30:40)
Revealing mistake: When the riders break out of Helm's Deep, you can see the hooves on some of the horses pass straight through the Uruk-hai corpses on the bridge. (01:29:10)
Continuity mistake: When Aragorn, Gimli, Legolas and Gandalf are galloping towards Edoras, then stop and when they are riding up towards the entryway at the bottom of the hill, Shadowfax has a white rope around his neck. However, as they're riding through Edoras, passing the people, Shadowfax no longer has the white rope around his neck. (01:12:30 - 01:16:20)
Revealing mistake: Shadowfax, the horse that only Gandalf is supposed to be able to ride, will not take a saddle and bridle, so throughout the majority of the film, they try very hard to hide the saddle that Gandalf is obviously sitting on, even though you can see him holding the front of it underneath his robes, and sometimes, you can see him holding a very thin bridle. But right at the end of the film, when you have the shot of Gandalf, Aragorn, Legolas, Gimli, etc. on horseback, you see Gandalf's feet in stirrups. (01:44:05)
Revealing mistake: When the women and children are evacuated to the Glittering Caves under/behind Helm's Deep, in the first shot, a hooded person leans on a stalactite making it sway back and forth. (02:42:00)
Continuity mistake: When Theoden is spouting his poem about the horse and the rider, Gamling is putting the armour on his King but when the camera returns to a wide shot, he still only has his breast plate on. (02:42:00 - 00:55:35)
Revealing mistake: Frodo, Sam, Faramir and Gollum are at the sewer in Osgiliath when Faramir asks, "Cirith Ungol?" and then grabs Gollum's neck. Frodo and Sam watch as Gollum is grabbed, but their eyes do not follow Gollum as Faramir grabs him, their eyes remain focused on the ground to their left. The shot of Faramir and the shot of Frodo and Sam were edited together, with Gollum added later. (01:42:20)
Continuity mistake: When Merry and Pippin first enter Saruman's storeroom, in the close-up, Merry is holding an apple and a large glass carafe with wine. As the camera pans out, to show the whole storeroom, he is no longer holding the large glass carafe, but he is holding an apple and a turkey. Extended DVD. (01:40:20)
Continuity mistake: In the opening close-up shot of this scene just before Gollum says, "We wants it. We needs it. Must have the precious," Frodo and Sam are seen sleeping side by side. In the next wide shot of them they are sleeping perpendicular to each other. (01:38:35)
Revealing mistake: At the Dead Marshes, Frodo tosses to the ground a piece of Lembas bread, for Gollum to eat. However, Gollum doesn't reach for the 'tasty' food in the same place that Frodo tossed it. Extended DVD. (00:43:25)
Continuity mistake: When Merry is running away from the Orc in Fangorn Forest he has a big gash on the left side of his head, yet when he's in Treebeard's hands it has changed to his right side. Due to shot/scene flipping, this occurs numerous times. (00:28:30 - 00:39:00)
Revealing mistake: When the men are retreating into the halls of Helm's Deep, you can see an archer in the bottom right corner repeatedly shooting his bow without an arrow on the string.
Other mistake: In this scene, Legolas says, "The Uruks turn Northeast. They're taking the Hobbits to Isengard." This is a mistake because Aragorn, Gimli, and Legolas are chasing the Uruks on a westerly course towards Isengard. If the Uruks had turned Northeast, they would have almost doubled back on the trio. (This is in the "Special Extended Edition" DVD.) The Uruks were taking the closest way to Isengard, across terrain, not traveling by common roads. In the book they traveled without rest. There's no reason to believe they would have diverted from their Western course to Northeast temporarily, that would have slowed them down. (00:19:00)
Revealing mistake: Right at the beginning when Frodo and Sam are climbing up a hill, look at Frodo's left foot: One time he makes a step and his Hobbit-foot vibrates when it touches the ground. Both his feet vibrate as he walks, when he has his cloak wrapped around him. (00:08:30)
Other mistake: It seems as though the Elves at the battle of Helm's Deep aren't quite as coordinated and elegant as Elves are rumoured to be. During the Helm's Deep battle scene, Aragorn is shouting commands to the Elven archers. In the close up shot of Aragorn while it's still raining, look to the left of Aragorn, there is an Elf who gets hit in the head by the quivers on the back of the Elf next to him. (01:04:50)
Answer: The movie makes it clear that Gandalf has lost some of his memory and his personality has changed. Gandalf actually did die and pass over to the "other side", as it were but was sent back to complete his task. However, he was sent back as a similar, but different entity. Gandalf the White does not have all the memories of Gandalf the Grey, at least at first. He doesn't even remember that he used to be called Gandalf the Grey until someone points this out to him. It is implied that Gandalf doesn't even remember Sam until Aragorn mentions him. Gandalf then searches his memories and remembers who Sam is and his eventual importance to Frodo's quest. When he finally remembers this, he is pleased that Sam went with Frodo, as he will play a crucial role near the end of the journey.