“Yes, I know. I know who’s the Thing and who’s not in the very end,” he said during an interview with ComicBook.com. But if you were hoping for any elaboration, then keep on hoping. “Nope,” Carpenter added when probed for more information. “Cannot tell you. Sorry,”
It was pretty much the same answer he gave SYFY WIRE last summer: “I know, but I’m not telling you … I just feel like it’s a secret that must be kept. The gods came down and swore me to secrecy.”
I had thought that part of that years-long process of script polish that it went through was embedding enough clues into the script that it’s possible to deduce who was really human at which points. There are little clues like randomly panning down the stairs at one point in a shot to show that a particular stairway is empty, or the guy walking down the hall jingling the keys and then off-screen you hear him drop the keys on the ground when he gets surprised by something, explaining how it was possible to get access to the locked fridge.
I don’t know the answer and I’ve avoided watching the Youtube videos which claim to break it down in case I want to try to sort it out for myself someday. But I thought that there was a puzzle you could solve that would lead to one specific supported answer.