You ever notice that in every news story about a dog attacking anything, the dog in question is always a pit bull? Always. And this despite that a pit bull isn't actually a breed of dog; it's a label. Kinda like "Assault Thingies."
Anyways, this is one jacked up story.
The cop very well may have been arresting a legitimate scumbag, or maybe not for all I know, and I presume that he was not in uniform. Uniforms are very important. They help identify police officers as bonded servants of public safety, and not one of two gangbangers fighting in your back yard at 1 a.m. that needs the attention of your guard dog. If I saw two plain clothes dudes rolling around in my yard in the dark, I'm certainly not going to take one of them at their word that they're a police officer and, like most folks, probably couldn't tell what the hell that shiny thingie is that one of them is shining a flashlight at. I definitely wouldn't fire a gun up in the air, either.
I'm glad everyone survived that mess. Too bad for the dog though.
Update: To be clear, I'm not denouncing the American Pit Bull Terrier, or any of the Bull Terrier breeds, just the overarching term "pit bull" that is branded on any dog that is worthy of a newspaper article. Some ugly mutt bites a kid and all of a sudden it's "PIT BULL GOES ON FEEDING FRENZY AT DAY CARE CENTER!!!" The label "pit bull" is the "assault thingie" term of the canine reporting world.