I bet that was caused by using standard wheel lugs and aftermarket alloy wheels

The alloy wheels are thicker than steel where the lug nuts pass through, and you should ALWAYS ensure that the amount of thread showing through the wheel is the same, or slightly greater than standard, and that you do NOT use closed lugnuts. How do I know? i have just fitted aftermarket wheels to the Alfa Romeo Spider. And the depth of the mounting section of the wheel was at least 12 mm thicker than standard. By using the same closed lug nuts, I was unable to judge by eye, how much of the threads were actually engaged. Had I NOT checked, then I would probably have had the same result as this guy. Only half the lugnuts actually being on the bolt, meaning only half the lateral loadbearing capability of the lugnuts was being used. they would have stripped in an instant, just as these did. All at once. Just as these did. But I might be wrong

can't see clearly enough in the video, bu it looks like all the lugs are there, not one snapped.
Nick