"Dramatic" video? If you watch the video without the "dramatic" sound turned on, there is really nothing of note happening. Everyone that can be seen is sitting in their seat. The one dramatic part is not part of the video at all: It is the still picture of the overturned serving cart, which is credited on the photo itself to another photographer.
I can duplicate that "dramatic" video on any flight, even if it is perfectly smooth...just move the camera around.
All the drama is in the narration. Watch it with the sound turned off, and discount the still pic of the serving cart? "Dramatic video"? "Blair Witch Project"?
Since the airplane turned around and made an emergency landing due to injuries, I have no doubt the turbulence occurred and was severe. We just didn't get to see any of that in the video. I cannot imagine it was anything other than clear air turbulence, which can and often does happen with no warning. Had there been weather involved, it would have been avoided and the captain would likely have kept the flight attendants in their seats while passing around the weather just to be sure.
I doubt the aircraft itself sustained damage. It was likely inspected by maintenance and flew off in short order.
As for the guy who hit the ceiling: Now he knows very well why passengers are told to keep their seat belts fastened at all times while seated. The FAA even requires a placard to that effect in view of every passenger.