A couple of thoughts... I would much rather have been in my Class C {Ford E-350 Chassis} than a class A that came apart like a cheap card table. Not much steel between the occupants of an A vs a C. Anyone in the front passenger seat would have likely been severely injured or killed.
Clearly the A driver was driving too fast without nearly enough following distance. When your lane becomes obstructed you have to be able to stop as you have no right whatsoever to the next lane over UNLESS it is clear and safe to move into.
The "2 second rule" of following distance is the bare minimum for most vehicles and when you are in 20,000+# of RV you should make that the 4 second rule.
I'm glad the driver walked away, hope he bought lottery tickets on the way home. I'm guessing that once lovely Precept was fully insured so all in all he got away with some less than stellar driving.
As always... opinions and YMMV.
:E