In the real world, the police officer will arrest you for recording him, charging you with:
1) interfering with official duties.
2) Resisting arrest.
3) Felony assault on a police officer.
Remember, in a criminal trial, you have to prove your innocence. How do you prove you did not do something that a police officer, testifying under oath in a court of law, says you did?
No you don’t, at least not in the USA. The state has to prove you’re guilty. Granted, I gather the word of an officer will usually trump an ordinary citizen, but that’s a great use case for the filming of Officers! It’s hard to prove interference with official duties when you’re quietly filming an officer from 25+ ft away.
So, if I have a constant video recording where the officer is clearly at a distance, wouldn't that be great for my defense? Much better than if that same video showed me walking right up to them, within touching distance, with the video not showing where my limbs are at all times.
If you're worried about unlawful arrest, stay away from the cop and record them -- and if you do that, great, this law wouldn't affect you.