Right here. Seeing someone with a gun is not even legal cause to stop someone in Pennsylvania, let alone draw a gun on them.
UPDATE: Listening to the whole video, and listening to the tone in the cop’s voice, I think that guy was actually close to being shot. Probably best to just keep quiet and be very compliant in that situation. The lawsuit can come later. I’m not sure whether it’s exceptionally brave, or exceptionally stupid to amp up a cop who has a gun drawn on you.