Assuming the driver had to do a panic stop, why blame that
automatically on the driver?

It would seem likely that you've never driven anything larger than a
U-Haul van, or you would realize the big, slow, cumbersome loads seem
to attract every nutcase in the world.

That "panic stop" may have been necessary to avoid flattening a Mini
Cooper that pulled into the space immediately in front of the tractor-
and slammed on the brakes. Have you considered that the skill of the
driver may have kept your boat *out* of a devastating
collision, rather than the driver's negligence was somehow responsible
for damage to a boat improperly prepared for transport?

The very fact that items in the boat were strewn about by the transport
demonstrates that the prep was not sufficient. Having to slam on the
brakes once or twice during a cross country is a probable occurence for
which one should plan and prepate.