Back to op,
I think that this case is different to most, the owner .....
Was aware of the dogs aggression
Had been issued orders to protect others
Failed to comply with these orders
Knowingly endangered the public
So I guess one could say that their behaviour was "reckless"
That being a very important fact legally speaking . Hence the heavy punishment.
As an owner of any animal you should control the environment not the animal itself .
Courts look at all the factors and I hazard a guess that the heavy sentence was a result of the reckless conduct rather than the severity of the bite. As it should be.
Good precedent I say ...
I know my dog attacks other dogs so I would be reckless to take him to a off leash dog park , if another dog entered my yard and got attacked I would not have been reckless. So same Result - dog attacked ....but my actions and culpability are very different in the 2 scenarios .
Jet