Don't squander your right to record in public on something as mundane and personal as a civilian minding his own business. Record a crime, at least. Otherwise the law may change and you may lose that "right".
There are, but they are extraordinarly unlikely. People push and shove each other all the time over minor insults and disagreements and almost never end up in front of a judge. Most cops would just say "you should have put the camera down when he asked you to, now stop wasting my time."
I also think in some countries it might be illegal to record someone either video or audio without explicitly telling or asking for permission. Even at the airport (at least in many I have been) it was not allowed to do video recording