FPV (first person view) means flying a drone with goggles on that receive a live video feed from the drone. The drone has a small security camera on the front of it and a video transmitter that sends video instantaneously to the pilot. The footage you see is from the GoPro, not the FPV feed. The FPV feed looks more grainy and is usually in 480p. At this resolution it is still very easy to see a person on the ground. The pilot in this video was aware of the people in the park and did not fly over or towards any bystanders.
While flying at a park in So Cal after a drone race, we crashed one of our drones. The crash occurred far away from any people, but one lady decided she didn't like what we were doing and stole our drone. The GoPro was recording the whole time and we got some amazing sound bites.
The police showed up and gave us our property back and couldn't have been nicer.
You may hear some obscene verbal abuse from the woman, so viewer discretion is advised.