I drive an 8 wheeled tipper, and literally without jacking the thing up to full height, there is no way that could get up there!

I had thought maybe the driver had knocked the tip lever while on the move, but

1) Most tip levers have safety catches (you have to manually hold the lever all the time for it to work)

2) You'd notice straight away. Even empty that's a lot of weight up in the air

3) The biggie - the tipper doesn't work unless a PTO is engaged, usually a dash switch, which would be hard to knock on or off accidentally.

So fook knows

Could the body have somehow become detached from the truck and been dragged behind the lorry? The driver saw this, so slammed on the anchors. Old giffer in the Corsa rams into the back of the truck body, forcing it up in the air using the back of the truck like a launch ramp. It jams under the gantry. Matey trucker legs it in the now chassis cab thinking SHIT!!!

Be interesting to see what suggestions people come up with or what ACTUALLY happened.

Si