New this month Continuity mistake: During the song "Blunt the Knives", Balin is seen in a shot from behind sitting at the end of the dining table. He is shortly afterwards seen dancing with a broom two doorways behind. The next shot then shows him sitting down again, bouncing plates off one he is holding.
Continuity mistake: In the scene where Bilbo spares Gollum's life, Gollum turns around facing the invisible Bilbo and extends his right hand out to a rock. The far shots from in front of Gollum show his arm almost fully stretched out and his hand away. But the shots from behind Gollum show his right arm bent on the rock with his hand much closer and level with his head.
Other mistake: Just after he arrives at the gathering Thorin states that he wouldn't have found Bag End had it not been for the mark Gandalf made on the door. Bilbo then claims that 'There is no mark on that door, it was painted a week ago'. However in the earlier scene where Gandalf makes the mark the paint work is cracked and weathered, more than it would have done after only a week.
Continuity mistake: The shot where Frodo walks back into Bag End with the mail and the shot where Gandalf knocks on the Bag End door in Fellowship of the Ring are apparently the same setting, but it is different between the two different movies. First, the grass around the bench closest to the door has long grass around it, but there is short grass in Fellowship. Second, behind the bench is some sort of bucket on its own. In Fellowship, there are a few things next to it that aren't even there in The Hobbit. Third, further behind the bench is a lamp post, about a meter and a half away from some pink flowers, that was right next to the pink flowers in Fellowship. Fourth, next to the window are some green flowers that cover half of the windows. In Fellowship, those green flowers are a much lighter green and cover the entire window. Considering only an hour passed between these two times it's hardly possible the flowers would grow, and since Bilbo was too busy working on his story, he wouldn't have moved something.
Continuity mistake: Shortly after Bilbo finds the Elvish sword that turns blue in the presence of Orcs and Goblins there's a fight with Orcs at the entrance to the hidden valley. However, the sword doesn't glow blue. In subsequent fights with Goblins and Orcs the sword does glow blue, even when sheathed.