It would appear to me that the person flying that cub is actually fairly experienced. Yes he was hot dogging the take off, but you'll notice that once the plane started rolling to the left, he didn't panic, he reacted quickly, added throttle, and stayed off the elevator. The maneuvers later in flight, and then the recognition that "somethings not right" and a nice line up and smooth deadstick landing are all marks of experience.

You are correct that these are all reasons why a beginner should not fly a cub (or any other plane for that matter) without proper instruction. Had that been a beginner without an instructor, there would have been toothpicks on the runway.

Brad