From a Legal perspective I would say that the dog was under control, on a lead and in a secure area. The difference here is that the boy put his hands into the garden, a question a court might ask is whether the dog was know for this type of reaction and if it was then were the steps you had taken responsible?
I think the behavioural aspect of this is more for parents to teach their children not to approach or pet dogs without the owners permission.
Sooty is a biter, but he never bites people he approaches, he will only go for people who approach him, this behaviour of his is getting much better and he is a lot more relaxed around people than when I got him from the pound. A technique I use to aid this is constant handling and controlled exposure, using friends as training aids.
I think people make a lot of fuss over muzzles, its not exactly a ball and chain or instrument of torture, and as mentioned it gives you the reasurance that you wont have to have him pts because of someone elses stupidity, and he can enjoy himself just as much, though in this hot weather make sure you get one that allows him to pant.
