If it was staged, it was done by idiots.
I have an email of a guy that mistakenly fired his rifle with a borescope in the barrel and it is unbelieveable the damage that occured. Three people needed medical treatment.
I have seen several 12ga shotguns fired with something in the barrel. Sometimes it is complete "grenade" work and others it is almost unnoticeable.
The wierdest one though, was a Winchester 30-30 with THREE rounds fired into a blocked barrel and no explosion, until the 3rd round.
Had a guy, that I actually admit knowing, fire a 12ga pistol flare out of his Browning automatic shotgun with a full choke. He said the last 4 inches of the barrel "was so white hot, they couldn't look at it". That was just last month.