If your standing in the same room, 6 feet away, the only way you can tell if it's the real thing is if you can see the bore....
Very nice BB gun! I think I'll buy that model. Especially like the sliding grip cover for access. The author of the video complained somewhat that it doesn't look quite like the real thing, because of the several screw holes! Pretty realistic imitation with the moldings to look real.
On another note, news reports now confirm the boy had an airsoft gun with the orange tip removed - it was not a BB gun.