Dogs don’t have to be big or strong to kill , a Jack Russell has ability to kill small child , fragile adult and have done in the past .
Not on the end of a size ten, it won't.
I've already covered that, earlier in the thread.
The issue in your example though isn't the dog: it's leaving a "small child" in the company of any dog, unattended.
Drop-kicking a ten stone XL over a fence is not an option.