Continuity mistake: In the 1982 movie, the alien ship is uncovered by the Norwegian scientists using thermite. (As seen on the films discovered by the Americans.) In the 2011 movie, it is uncovered when the Thing gets back into the ship and starts up the engines.
Continuity mistake: Near the end, when the dog-thing escapes from the camp look closely, its not the same dog, that's because the standin is a different dog altogether.
Continuity mistake: When Kate scoops up the fillings with a tissue after discovering the blood in the shower, the tissue and blood shrink and change between shots.
Continuity mistake: When Carter tells Kate to put her headset on in the helicopter, the microphone on her headset moves closer and further away from her face between shots.
Suggested correction: It is also established in this film that the creature cannot perfectly imitate inorganic materials; the tooth fillings, metal plate, etc. Kate knows that Carter is The Thing and asks him a trick question about his earring to confirm it. The fact that The Thing reaches for the wrong ear means that it didn't know where the earring really was because it cannot perfectly imitate inorganic materials. There is no mistake here.
THGhost
The mistake has nothing to do with The Thing not being able to imitate inorganic material. The mistake is The Thing has all the memories and thus should know which ear was pierced based on these memories.
Bishop73
This goes with my theory that he was actually human because he didn't try to assimilate her when they we're alone and far away from people, and he didn't change when he was threatened and accused which was backed by (potentially false if the theory is correct) evidence which would make it defend itself.
You're obviously wrong here. The Thing imitates the human perfectly including the memory and I'm pretty sure that if you only have one ear pierced you'd know which one is it, therefore the imitation would know.