Cops can get away with anything
Handcuffing a live witness to a corpse, carrying a shotgun around in public, going into a drug den with no backup and shooting and assaulting people indiscriminately, assaulting the father of on of his students in public, unprovoked. And I can guarantee you he would not get in trouble with his department for any of these things. Real life police have done so much more and have been acquitted or never even charged in the first place.
Seriously, if you're a cop you can do these things. If you don't like the way someone is driving, follow him home while you are off-duty, never identify yourself as a cop and pistol whip him in his own garage and then put the gun to his head and tell him you're going to kill him. Your own department will do an "internal investigation" and find you did nothing wrong, and the DA will refuse to indict you. This exact situation happened in real life in my county.