Revealing mistake: When the master's gold falls into the water off his boat, several of the gold items can be seen floating, something no gold item should. (00:40:00)
Revealing mistake: When Gandalf shakes Bilbo's hand it should be a lot bigger than his but it is the same. (02:25:26)
Revealing mistake: During the battle of Dale, Bard confronts Alfrid, who is dressed as a woman and is trying to escape with looted gold. During the confrontation a troll climbs over the parapet and is killed by Bard. As the troll falls, Alfrid also falls. When he lands, the ground near his hand ripples like fabric covered in sand.
Answer: In both the novel and the movie, Alfrid's (who is not named in the book) fate is unknown. Beorn, in the book, stopped his reclusiveness and became a leader of the local woodmen and protected the area from orcs and goblins. He died sometime before the War of the Ring and was succeeded by his son Grimbeorn.
Greg Dwyer