Anyone who owns a powerful dog, be it pit bull or any other breed, must act as the pack leader. It doesn't matter what the dog has been bred to do. This dog attacked because it saw itself as the pack leader protecting its territory and pack. If the owner had been the pack leader, the dog would not have attacked unless told to. Submissive pack members only do what the leader tells them to do. They are not even allowed to eat until the pack leader says so.
Yes, I blame the ignorant owner.
That why a breed ban will be effective. It's obvious that few folks are capable of being Alpha with these bred for fighting creatures.
Spay and neuter existing Pits, euthanize the maulers, then ban breeding them. The fighting dog as a pet experiment has failed.