You technically did not break any of the rules, in essence because the professor was given these items to use in the gallery it was his problem. The TV was not changed back to the right channel and the necklace being taken and worn was no fault of yours either. I think the professor paid the price, I would have ran and not looked back as well.
Hopefully whoever takes over the gallery reads the rules - also sounds like they need a sign in so they know peoples last names!