You meet a lot of arseholes in life but the ones in uniform are tricky to deal with and there are plenty of them.
Trying to juggle the power imbalance and your own dignity is the tricky bit, I've got it wrong before and had to listen to loonies yelling and talking to themselves all night, I've bit my tongue a bit since then but when you get an aggro arsehole it's a battle to be civil.