Clearly it wasn't - it was laying halfway out of the yard by the time it slid to a stop, which means it was in a full charge.

Besides that, how is the father to know that there was a shock collar on the dog?   Think.

No, this is the fault of the owners by having a poorly trained animal that was aggressive to humans.    They knew it, Animal Control knew it, and so did the man defending his child and himself.

If anything, the dog's owners need to be charged for endangering people with their poorly trained dog and allowing it access to attack people with a shock collar that may or may not work.

There's nothing worse than people who have dogs and don't know how to train them from bad behavior.