Whatever it was it had some spread on it. Another possibility is that something in that gun barrel disintegrated and let loose with metal fragments. There are all sorts of accessory add-ons available to achieve various effects. Or it could have been something as simple as a cartridge fragmented and left bits in the barrel, in front of the chamber, to be propelled at high speed by the succeeding blank. Maybe it was something along those lines. Pointing a gun at a person in those circumstances should just feel very wrong to a reasonably sane person, and that's why it's just not done.