That's your impression from the media. In reality it's an illusion. Just because I can lawfully do something doesnt mean I wont get yelled at for it by my admin later.

Yea I can technically impound grandmas car and take her to jail because her physical license isnt in the car with her, even though I can find her in the computer in seconds.

If I did that though I'd be asked wtf I was doing and they would seriously consider firing me.

SOMETIMES that same scenario is used and encouraged, like when you have a homeless guy causing problems all over town. You cant lawfully tell him to leave your town, you are forced to respond each time he runs into a new store and ban him from that store.

To avoid dealing with him all day and wasting tax payer money, sometimes you can find a loophole arrest to lock him up for the night. These aren't used maliciously but rather to solve problems for the general good.

Criminals use loopholes and so do police, but using loopholes out of malice will not be good for your career in most departments