Excellent Training Video
The first time I viewed the video I did not notice the spoiler handle sneaking back. This can happen to any of us by human error or mechanical forces. The video shows how easy it is not to catch on to an insidious situation.
I would show it to pre solo students and also play a video of a canopy opening on tow.
Lastly I know three instructors who wrote off gliders when solo. Hopefully the accident pilot will some day be in the back seat.