You know I might wonder if I had clicked x accidentally if it had not been doing this same thing even before I knew that "Post" was up on the menu. It would do this when I tied to go to another screen. Besides I am 99% sure I clicked post.
It has happened many times over the last year or more. Numerous times I didn't even notice that it changed everything back and ended up listing an item with a totally inappropriate description.
It does this (converts back to the old text) or gives me html gibberish of the previous description.