Tell that young man who was shot in the face for trying to take his seat belt off when he was WRONGLY pulled over that he is an "urban legend".
OK, OF COURSE there are occasions when innocent people are shot/injured. It's part of the cost of having undereducated, inexperienced young cops on the street. The fact is cops come from the human race and therefore, are subject to human frailties.
The fact is, if these incidents were not rare, they wouldn't be newsworthy. The statistics are that society is safer because of the presence of cops than it would would be without them. Dogs bite people every day: Not news. Man bites dog: News. Get it???