We all eagerly await your answer. I may even forward it to Yale.

I've given my explanation, what's yours?

You have your explanation. The line failed with zero chaif and looked fine. You
just can't believe that a label could lie to you or a line could simply fail
under repeated loading.
On the other hand, sailors I know differ and add safety lines because they KNOW
you're wrong.
Play the odds with your boat if you like, but stay clear of mine. 10 years and
never any damage from tie ups. And you know we get a handful of nasty blows
through here every year.

Yale is still waiting!!!

R