Catastrophic failure of an improperly stressed suspension component. The wheels and tires that come with your truck or other vehicle were chosen by the engineers of those vehicles. Within limits, deviations are OK; push those limits, and you’ll have all kinds of handling issues and component wear.
Elsewhere, someone said it looks like a wheel spacer failed. That pickup truck didn’t leave the factory with that part.
Using stop motion, you can see a brief flash from the shiny brake rotor as the wheel tumbles at the end of the clip. It’s hub must have gave up where it bolts on to the suspension. Losing lugnuts wouldn’t kept the rotor with the wheel.
From my trucking years I’ve seen a several failures from this idiot ‘it will be just fine’ mentality.