I grew up in a household full of the so called rabid type Pig dogs, and have raised a couple of straight out Bull Terriers since adulthood, with no issues coming even close to these incidents(except for the feral pigs that is).
It is a shame that sheople are so easily fooled by the media into thinking just because it is a certain breed of dog it must be a natural born wanton killer.
Completely not true, as said, the Dog Whisperer basically just preaches a bit of common sense, of which is not so common. The dog is just a product of its owner.
The owner should be held accountable for anything that the dog does, just as if you had any other type of weapon and didn't handle or store it in a safe manner.
Either way I would have just kicked that mutt into next week, and found the owner for the next serving(no knife necessary).