I do not see the point of his video. Of course the gun when bang and pellets came out. How could they not?
What he does not show is whether the barrels are scored or the chokes (did he say how much choke?) swelled. And what were the loads exactly? 40 grs of Goex 2f? Or something more reasonable? Looks like he has a single, lubed, Circle Fly wad. No overpowder wad of any sort. I would wager that they were very anemic loads. Without a lot more information, there is really nothing to be learned here.