According to Yahoo News, the car got stuck on the Radiator Grill of the Lorry.
The Mobile Phone Video isn't very clear so you can't tell if the Lorry driver's braking or not, but even so there is no way the lorry driver couldn't see the car, as most lorry's in the UK are Cabover's (Cab Over the Engine), so the Driver's have better visablity plus most now have a mirror by the Windscreen to see down infront of them, so I reckon it's Road Rage.