I'm not taking your words out of context, you said it yourself and I quote it
"Try using physics in a LAW COURT. See that you'll get laughed right out.", my english is horrible, maybe I misunderstood.
I know wikipedia isn't a great reference but take a look at this
http://en.wikipedia.org/wiki/Human_height
Scroll down to "in sport" section, it's got a small explaination of how "physics" "height" are relating to "sports"
Like I said before, this is just an attempt as a warning for using underage girls, just a prevention method for future competition, it's not a cheap shot at the girls, at best it's a cheap shot at the Chinese gov.
Watch, a few days later when they have track and fields and the athletes that american "bought" from some african country wins they'll talk about that shit too, it's just the nature of the game.
PS: You should watch that show "sport science", it really explains alot of stuff about sports/math/physics, pretty cool show if you have some free time.