So an eight month old puppy tugs at a child's shirttails and the dog needs shooting?
I guess I should have shot the neighbor's dog the other day when it did the same thing - chased my BF's (running) son and tugged at his shirttails. Of course, he's not a pitbull puppy, he's a Boston Terrier or some such breed. He's also harmless.
It's too bad that hysteria over this breed leads to such ignorant knee-jerk reactions resulting in death of a human (and likely the dog, too, as he'll doubtless be put down to assuage the grieving family's hysteria).
Did the dog even bite the man? Probably not. A pitbull determined to bite him would have drawn some blood before his wife did.
A puppy. Doing what puppies do.
I'm not laffing.

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
~ Carl Sagan