Just curious, how did you get a videotape?

I wish I had an "Oh boy, here comes a police officer" button, which records the entire event. But obviously there is no such device.

I'm terrified at the idea of pulling out a cameraphone during any police interaction, due to the possibility of being prosecuted / imprisoned for violating their expectation of privacy. I'm relatively poor, and no one really cares what happens to me, so I wouldn't be able to fight the courts.