 CONT: When the Arnold talks to the goblins in order to save the  girl, he is standing in front of a big tree, then when the spear is  thrown and it hits him, he is standing in front of a different tree.  Also, the background during the shot of the spear flying toward  Arnold is clearly different. According to the cast members, this is  because that was shot a few miles away, in the same area as the  goblin ("troll") church.