I immediately thought of a past Mythbusters episode. Actually, it was more Darwin Awards. Could this really happen?
Based on the dimensions of the balloon, it could have contained enough helium to lift a 50 pound object. Based on University of Google, it takes a 15 cubic feet to lift 1 lb, CNN says the balloon was around 20" across x 5" high so ((pi * r^2)*5 = (3.14 * 10*10)*5 = 1570 ) . However, forget the physics for a moment. Take a look at the balloon in flight and at takeoff. If there had really been a 50 pound boy in the base it would have looked like an upside down teardrop and there's no way it could have lifted off so lightly.
Another fine example of media manipulation.