While they should take any measure necessary to protect life even at the risk of their own, cops simply aren't conditioned to calmly wade into gunfire the way soldiers are. Soldiers are inoculated to the sights and sounds of combat via ad-nauseum exposure (because that's all soldiers do is train for war). Cops just don't get that training and conditioning, so it's asking a lot of a cop to throw himself into gun battle with no regard for his own safety. It's an extenuating, alien experience for the cop.

While they should take any measure necessary to protect life even at the risk of their own, cops simply aren't conditioned to calmly wade into gunfire the way soldiers are. Soldiers are inoculated to the sights and sound of combat via ad-nauseum exposure (because that's all soldiers so is train for war). Cops just don't get that training and conditioning, so it's asking a lot of a cop to throw himself into gun battle with no regard for his own safety. It's an extenuating, alien experience for the cop.