The camera was attached to a remote control helicopter and the GoPro was without the case.
This was recorded early in the morning, a few hours after the gates of the park were open. It seems to me that the wind makes the helicopter unstable so it makes it fall in the VIP zone near a guy as you can see. Then some staff from Lollapalooza caught it so i could found it.
This video was cutted from the original one which is a minute more longer.