Why risk confiscation of your camera or arrest when cameras and recoding devices can easily be concealed? There are many eyeglass camera/ microphones on the market at reasonable prices.
I do understand that many want to assert their rights by openly taping police in public. So, the next time one of these incidents occurs, make sure that one individual has a concealed camera.
No, have one annoying person with a phone, and another with a concealed recording system. Good distraction and confiscating the phone will make them overconfident.