Many here are saying "double-charge/overcharge". I disagree.
I wasn't there, during the filming of the video in the OP's link. BUT,,,,,
As others here know, as I've said it before here, I too have had a rimfire rifle explode on me. To such an extent, and to such a noise, that it attracted others in the area and they came running.
I brought it in to my Gunsmith Instructor (I had taken classes at the time) and he explained to me and the whole class, that the volume of the case does not hold enough powder to create the pressures required to do all the damage to the barrel, receiver, stock, scope, my glasses, and my forehead. He stated that the ONLY way those pressures could be attained, was due to over-priming.
And yes, I did find out after-the-fact that there WAS a recall going on, regarding the ammunition I was using. The ammo company did take my rifle (it was my first, so I was sad to see it go), the spent/destroyed brass, all my remaining ammo, and my glasses (Serengeti's). They replaced it all, and offered to cover my medical bills too, but this is Canada so I didn't have any. But yes, I did have to go get brass shrapnel removed from my forehead. If it weren't for the Serengeti's deflecting it all 'up', that shrapnel would have gone straight into my eyes.
True story, I actually WAS there, as this happened to me. YMMV, do with that what you will. And yeah, this happened back around '93-'94 era.