Continuity mistake: After seeing the Mûmakil, Frodo and Sam are captured by Faramir's men. In the close-up shot as Frodo says, "We are bound to an errand of secrecy..." he's being held by one of Faramir's men around the shoulders and Frodo is holding the man's forearm. A second man is close to Frodo's left whose right hand is down. In the very next wide shot Frodo is holding the man's arm differently and the second man to his left is not only further away, he's standing differently and grasping the hilt of his sword in front of him. In the next two close-ups of Frodo, he's holding the man's arm exactly the way he was in the first close-up. It's also obvious in the wide shot that it's the scale double of Frodo. (01:45:25)
Continuity mistake: At the beginning of the scene, Sam is cooking the rabbits. Behind Gollum, Frodo's coat and pack lay on the left side of the overturned stone carving. In the following close-up, when Frodo goes over to his pack to take out plates and spoons, his coat is now on the right of the overturned carving. In the next wide shot, it's on the left again. (01:41:50)
Continuity mistake: Helms Deep's gate is destroyed by a battering ram, and shorn up like a barricade while Aragorn and Gimli hold back the orcs. However, when the orcs finally burst through the gate, it has reverted back to a fully intact gate that opens as if on hinges.
Continuity mistake: Just after the Warg knocks Hama off his horse, in the wide shot, Hama is lying in short green grass and his sword is flat. Then in the first close-up of Hama, he is lying in thick, tall, yellow patches of grass and his sword is sticking way up to his left. (00:08:50)
Continuity mistake: As the people are fleeing from Edoras, many shots are shown of Eowyn, and frequently her hair is arranged somewhat differently. (00:08:15 - 00:10:00)
Continuity mistake: In the stable at Edoras, Éowyn gives the saddle to someone, then starts to walk towards Aragorn, and her long hair is spread out all around her shoulders. Cut to the close-up shot, and her hair is now parted at the neck, hanging straight down in front and back. When Aragorn walks away, her hair is all around her shoulders again. (01:31:40)
Continuity mistake: At Edoras, as Wormtongue sits on Theodred's bed speaking to Éowyn, she says, "Leave me alone, snake!" As she stands we see Wormtongue's back, and the fur covers draped over Theodred's legs and all around the foot of the bed. In the next close-up of Wormtongue, he says, "Oh but you are alone," we see Theodred's legs slanted and no fur cover, just the white cover. Cut away to a shot of Éowyn, then back to Wormtongue, and the white cover on Theodred is lying differently on him and some of the fur cover is now seen. Wormtongue did not change positions between shots. (01:14:15)
Continuity mistake: In this first shot, there is a close-up of Legolas releasing an arrow towards the oncoming massive Warg attack. Then a wide shot of the hill, with Legolas still letting loose, and in the background, the riders on horseback coming over the hill. To Legolas' left are two riders on horseback that are just passing him. They are Gamling and Gimli. But in the next shot, Gimli is just coming from behind Legolas, and then Legolas leaps onto Arod. (00:10:30)
Continuity mistake: Merry wakes up to find Pippin drinking the Ent water. During this scene, Merry's cloak changes, to either with or without leaves on it and the amount and position of the leaves vary too. (01:08:15 - 01:10:00)
Continuity mistake: At Henneth Annun, Frodo and Sam have their blindfolds removed, and to their left are two barrels. In the 1st shot, one barrel has a brown cloth draped on it with a bowl of nuts and cracked shells and on the second barrel, candles that are not lit. In the 2nd shot, Faramir walks in and to his right the brown cloth under the bowl of nuts is draped differently, the candles, which are lit now, are a different variety and there are also ceramic jugs near the barrels now. After Frodo answers, "Yes. For my part," Faramir gets up and as he walks, the items on the barrels look the same as in the first shot. (00:29:00)
Continuity mistake: While running in Fangorn Forest, Aragorn stops kneels down and then says, "These are strange tracks." In the wide shot preceding just as he kneels down, and in the close-up when he says those words, his position and the position of the rocks and trees surrounding him are very different in both shots. This has nothing to do with camera angle. (00:50:55)
Continuity mistake: Aragorn, Legolas, Gimli, Theoden and others are in the Keep after the walls have been breached, while Aragorn is talking to Theoden about riding out together and the like, Legolas and Gimli are tipping tables up and putting them against the door. However, in one shot when Aragorn is asking about a passage to get the women and children out look behind him, Legolas and Gimli are standing with their weapons drawn, then in the next shot they're back to tipping tables up.
Continuity mistake: What happened to Aragorn's wounds on his shoulders after his fight with the Wargs? When he talks to Theoden on the outer walls of Helm's Deep, the blood is pretty much gone, only the fabric is stained. Later, when he and Legolas have their little heated discussion about the defenders of Helm's Deep, the blood is back again on the skin. (01:55:00)
Continuity mistake: During Theodred's funeral, as the bearers of the body lower Theodred off their shoulders, there's a close-up of the soles of Theodred's shoes. As Éowyn starts singing, the body's being passed towards the tomb. There's now another close-up of the soles of Theodred's shoes. The marks on the soles, of the right shoe in particular, are quite different in both shots. The helmet doesn't block the view of the soles on the shoes in either shot. (01:24:45)
Continuity mistake: After the shot of Gandalf, Aragorn, Legolas and Gimli riding towards Edoras, there's a close-up of Theodred. In this shot there is a red pillow next to Theodred's face on his right. In the wide shot behind Éowyn, there is no red pillow to the right of his face. Though there is in this shot a white pillow corner leaning on the headboard, that is not in the previous front wide shot. The fur cover at the foot of the bed lies differently in the front and back wide shots too. (01:13:35)
Continuity mistake: After the tree has buried Merry and Pippin in its roots, the close-up of those roots (gnarled and twisted) do not look anything like the roots of the tree in the far shot (straight and broad), when Treebeard says, "Away with you, you should not be waking." Not a case of distance - in the wide shot when Treebeard arrives, just after they're let go, you can compare that shot to the shot just before, and the roots are very different, regardless of the Hobbits' size. (01:10:45)
Continuity mistake: Just after Treebeard stomps on Grishnakh, with his left leg, he leans forward on that left leg, then Pippin yells, "Run Merry!" Then we see in the side shot that Treebeard now picks up his right leg and starts to move it forward. Then mid-step, in the next front shot, we see that Treebeard is now putting his left foot down, not his right. This has nothing to do with camera angles. (00:39:35)
Continuity mistake: As the Uruk-hai charge the walls of Helm's Deep, the elves release their arrows first, no problem here. However, when the Rohirrim shoot, the arrows that strike the enemy are not the short, brown-leather fletched arrows that they should be using, but the long white-fletched elven arrows.
Continuity mistake: During the scene when Frodo, Sam, and Gollum are in the Dead Marshes, Gollum begins saying, "Once it takes hold of us..." Gollum moves closer to Frodo as he reaches for the Ring, and then Frodo slaps his hand away as he says, "Don't touch me." You can tell that Gollum was very close to Frodo, however, in the next shot, after Frodo bats him away, Gollum is much farther away than he could possibly be. (00:44:20)
Continuity mistake: After Aragorn asks, "What do you fear my lady?" in the following shots the hair at her shoulders changes position between the front of her shoulder and behind her shoulder, in the different camera angles. (01:35:00)
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.