Most people have one leg shorter than the other..it's not some strange ailment. He was injured a lot, though; think he did right by NZ when we needed him.
U wot? That's like saying most people have one ear/eye/nostril bigger than the other. I haven't noticed this. Yet.
AFAIK most people have one 'dominant' side that is longer than the other - it might just be by 20mm or so, but it's there. It's common. Obviously if it's a lot shorter then you'd just be walking in circles all day and not be much use as a pro footballer..