I'm not a person who alleviates personal responsibility at all. I also think there are times that companies or government agencies should be held criminally liable, rather than just civilly, if their design flaws cause personal harm.
In this case I believe the companies could be held responsible, and here is why: They are designing these bed RVs to add much more weight behind the rear axle. The weight ratio that far behind the fulcrum is a problem and it's showing. The trucks are designed for weight to be in the bed where both axles and frame are bearing the load. Every one of those pictures are showing a big portion of the weight about 4' behind the rear of the bed, which is an even bigger problem for short beds.
IMO that is a big design flaw, and should cause the responsibility to be shared with the driver, as the intended design is part of the flaw.