"My point is that without recovering the boat and knowing for sure what damaged occurred, one cannot go on about inappropriate rudder size or post scantlings. Speculating that the boat did not have rudder stops is silly unless you can provide evidence of that. Only two things are perfectly clear - they had poor webbing design and welds and they made errors in the installation. Nothing is known or clear at all about the rudder post itself."

It's clear the rudders web structure failed from the spinning rudder. It should be easy for the builder to figure out what failed in the rudder structure. We can't really say how powerful the forces were that overwhelmed the structure, but they can easily build a stronger rudder now.

And of course they can do a better job on connections to the shaft above.