Being in an accident is a scary thing, most of the time it's a violent collision that stops both vehicles in their tracks. Not in this case!
:30 into the video you see the driver of the smaller car had windows smashed and both airbags had deployed. Indicating, that this accident was indeed serious and something needed to be done, mostly the stopping of the semi.
My brother is a truck driver, and he's told me that there are some big delivery's he's done in his life...so I can see how the truck driver didn't feel the impact, but how did he NOT SEE THE CAR DANGLING FROM HIS TRUCK?!?!