The tree with the carving that gets defaced is obviously foam rubber as it moves and splits apart.
In the featured review for this episode, the reviewer wrote about the number of appearances Angela Lansbury made on the show, they wrote that Angela made one appearance as "Jessica Beatrice McGill Fletcher". This is incorrect, as that is the full name of the show's main character, which Angela portrayed on all but one episode. The one episode where Angela didn't play "Jessica Fletcher," she portrayed "Emma McGill," Jessica's English cousin.