"So the bodies were fully interactive, you could blow parts out of their limbs and they would shift, move and flop according to the law of physics." yeah mighty fine, nothing new though. but developers always seem to forget what a body weighs. most ragdoll effect the bodies are bouncy and very light... not realistic

I don't think it is as much forget as knowing what works. You don't go flying through the air if you are hit with shotgun pellets either, but it sure looks good on film. Don't forget that it is meant to be cinematic and have that WOW effect, not portray reality. Reality is much too boring and nasty.