I agree the dog sounds like a show bred GSD and not necessarily suffering hip dysplasia. The rear ends on show GSDs can be pretty terrible... But they are normally all from hip scored normal parents. Just a sad trend in style...
I'm a bit confused though, was it a bite, or was it a scratch from a jumpy, mouthy pup? Did the pup have scratchy puppy teeth or heavier adult teeth? It sounds like your injury is more likely to have come from being grazed by a tooth than from being bitten down on.
Some pups are very mouthy and wave their mouths about a whole lot. Very easy to get scratched by them if they are leaping about like loonies.
I'm not trying to make excuses, it just sounds to me like more of an accident than an aggressive incident. I have a litter of pups at the moment and am covered in scratches from teeth and claws, and they're only little!