If you slow down the video filmed from the right side of the aircraft, then something happened about 5 seconds before it hit the fence. Maybe that was the right inner flap coming off. Then there is a fluid leak all the way.
The video I'm seeing is so blurred that I'm not sure if the 'fluid leak' is real or if it's just the light-colored lower fuselage seen through the gap between the (still present) inboard and outboard flaps. If it is real it would just about have to be fuel rather than hydraulic fluid to account for the volume.