A friend of my neighbour did exactly this, apart from as he's not as fat as the chap in the video he was going rather quicker .
On a downhill he ran into the back of a land rover defender parked half in a gateway, half on the road (legally), with it's tailgate open.
Poor bugger broke his back!
The fault was put on the land rover owner by the cyclist, but they got nowhere as the farmer was parked legally.
As an aside, on my way home from work yesterday I actually saw a cyclist not dressed in black!!!!! He was wearing a yellow Lycra onsie or whatever you call them, but no Frickin lights on an unlit country road. I did wonder if he made it home.