Cops have zero right to not have their feelings hurt. The only time I think something might be able to be done is if they are screaming in their face where they could damage their hearing, which is kind of assault, or things as I've mentioned like disturbing the peace, which should have a high bar.
Citizens should be able to protest the government with free speech. Everyone should have the right to tell an MP or police officer to get effed.
No one has the right to stand a foot in front of your face and scream obscenities at you. You don't have the right to do it to a police officer yet that is what happens to them at protests quite regularly.
Maybe the cop should have the right to deck the son of a
**** just like I would as a private citizen.