Re: THE THING (2011): Discussion, Spoilers, Reviews
And, yes, she comes to the conclusion after not seeing the ear ring because as she said earlier in the movie, the alien cannot duplicate metals, only the creature itself. It wouldn't be able to duplicate the earring and I doubt it'd even be able to duplicate the hole in the ear. And when she asks the guy about this he even reaches for the wrong ear he had the ring in. This all clues MEW that he's a thing.
I tend to think we're intended to wonder whether MEW was right or wrong, since he had a lot of other things on his mind and could have just forgotten what ear he used. if he'd already been duplicated at that point, he could have easily killed MEW and lifted the ship off rather than helping her, or alternatively could have simply stayed on Earth to spread.
"If you think you're brave enough to walk the path of honor, then follow me into the dragon's den."