With an Illustrator document open I clicked the Learn icon in Control panel, and chose New Features and clicked to watch the Properties panel movie. I quit AI and the movie began to play again… I hadn't quit it.
there was no way to stop it. I muted the computer and restarted AI where the movie resumed and I could stop it. I resumed it playing and quit again and it quit the movie this time. so I couldn't replicate it—but it was odd!