Grognard: If it was a slug, I suppose it is possible.  Highly unlikely, but not a zero probability.

Or, perhaps his friends weren't really all his friends.

A standard buckshot round holds 8 pellets, that are each .33 of an inch in diameter.  When fired from a shotgun, each of these pellets has a velocity of 1325 feet per second.  A .38 special fired from a revolver has a muzzle velocity of only 679-980 feet per second, and a .357 magnum has a velocity of 1,500 feet per second.  Each pellet of 00 buckshot has more killing power than a .32 revolver round or a .380 auto pistol round.  Some would argue that it is on par with a .38 special.  

Shotguns are considered short range weapons because they are only accurate out to 50 to 52 rounds, but the lethal range of a shotgun pellet, when using 00 buck, which it sounds like they were using, is much further than that for anything down range, you just can't be sure if you will hit it or not.  

Shotgun pellets can and will ricochet off of metal.  If they ricochet in a direction opposite of the one the direction they were traveling, they lose their lethal velocity pretty fast.  If however, they ricochet at an angle, which is far more common, they can be lethal at a considerable distance. 

My guess was that he was either standing at very close range to a metal target, possibly an iron shooting target that is designed to spin when hit, or else was standing at a 90 degree angle from such a target, at what he wrongly thought was a safe distance, perhaps to get a cellphone shot of the metal target getting hit.  My personal thought was that they were probably shooting at metal objects to make a youtube video, because you will find numerous such videos on the internet, of young men shooting at old appliances and computer motherboards.

Guns are not toys, but once again we have a tragedy where a young man needlessly lost his life, because he and his buddies wrongly thought that guns are toys.  Hell, the military doesn't allow 18 year old soldiers to use firearms, either in training or even in military operations, without strict supervision from much older, and more mature NCOs, and those kids go through a hell of a lot of safety and accuracy training.  However, we have no problem letting teenage civilians run around and shoot guns unsupervised, because it is always what we have done, and every time a kid dies in an accident, we just shrug our shoulders, and figure it is just one of those tragic accidents that happen, that can't be prevented in anyway, like when an 18 year old dies in a car crash because he was driving in his high performance sports car.  I mean you can't tell me it is a stupid idea to trust kids with things that can kill them and others?