Update: John Carpenter has weighed in on Twitter, throws cold water on the whole theory! Aww.
Giant Bomb userPM'd this to me, and I simply had to pass it along.
"When you guys were talking about the ambiguous resolution to The Thing, it reminded me of a film analysis I read of the Thing in college, namely that the bottle of alcohol that Kurt Russell and Kieth David share at the end of the film is actually one of the bottles of ether or fuel that Kurt Russell was using for molotov cocktails. Kurt Russell never actually takes a drink of it, but Kieth David does. A human would know the difference between drinking a bottle of ether or gasoline immediately, but the creature has no reference for it, or a gag reflex that an actual human would have when drinking it. It drinks the bottle, imitating a human, not knowing that it was a trick on Macready's part to prove whether David's character had been taken by the creature or not."