Is the lane clear? No. Is the lane clear? No. Is the lane clear? No. I’ll pull over then

The driver of the camera vehicle could’ve moved back a bit, sure, but without actually completely slamming on the brakes there’s not a great deal they could’ve done. The guy with the caravan really should’ve stopped trying to move over, especially considering he was trying to cross the chevrons, which you can’t do…

https://www.youtube.com/watch?v=Oy_1sLebvkk

A bit better quality, complete with swearing, here.