Do we have a AI with a theory of mind or just a AI that answers the questions in the test correctly?

Now whether or not there is a difference between those two things is more of a philosophical debate. But assuming there is a difference, I would argue it's the latter. It has likely seen many similar examples during training (the prompts are in the article you linked, it's not unlikely to have similar texts in a web-scraped training set) and even if not, it's not that difficult to extrapolate those answers from the many texts it must've read where a character was surprised at an item missing that that character didn't see being stolen.