I didn't read the story you linked, anecdotes of unrelated stories have proved to be unhelpful in rationally discussing ~this~ case. So a cop has in the past made a bad shoot. If that's proved I'd argue it that way. But it doesn't make a bit of difference in assessing this case. You simply can't make sweeping statements.... well, you can, but you betray your bias when you do.
I did discuss ~this case~. Repeating: "...the girl was calling her dog back and instead of simply waiting for it to retreat, they shot it." There was no need for them to shoot it. They could have waited for it to return to the girl, had her or her parents secure it, then followed up with the inquiry about guns that originally brought them there. The shooting was unnecessary and cruel.