Wreck. Man what a bummer

If I had to guess, he didn't have a lot of bodywork under the bed cover, and air pressure got under it and lifted the cover, which acted like a wing and lifted the rear of the car.
I've seen lots of trucks where they just cut the bottom of the bed away for tire clearance or suspension, or other, and they don't bother to cover the bed. Looks like a good reason not to.
I don't remember seeing anyone go to the back of the truck to shut the electrical off. They may have, i didnt see it.