I don't know if you're very much familiar with John Carpenter's The Thing, but I was reading an article a few weeks ago about whether MacCready or Childs at the end where the thing. I believe it was a comment on the article that suggested that MacGrady had given him gasoline instead of whiskey to drink from, and the alien would not be able to tell those apart, so that would be proof it was Childs.
Been a while, but hopefully I get to catch that movie again and see if that looks like what's actually happening. Then again, if it was, pretty sure everybody would have been all over that already. So probably not.
