Invisible Silencers
Notice how the witnesses to this Air Soft gun battle would not have heard any noise, perhaps other than the "click" of the spring-powered mechanism snapping the plastic BB out the plastic gun barrel.
So the witnesses must have assumed that the kids were not only shooting at each other, but with silencers. Invisible silencers, since there was no can on the end of any gun's muzzle.
And since nobody actually got hurt in this gun battle in public, they all must have been wearing body armor. That's why they just said "ouch" when they got hit and kept on playing.
I'm sure the witnesses thought that plenty of real firearms came with bright orange muzzles and clear plastic frames.
Yeah, it's reasonable to me. Darn hooligans. No respect, I tell ya.