Interesting looking at the investigation report photos... The "top down" picture showed a very shallow draft mainsail in my eye. Must be due to the speeds involved (or the ability to really flatten that main).

The close-up on the traveler line (I turned the pic sideways to see it better) mirrors Jake's view: It looks like the tail of the mainsheet is tapered, with the core splitting in two directions right at the traveler. This core appears to join the orange line which looks like some sort of 2:1 arrangement on the traveler end with the line terminating back at the traveler.

I am hypothesizing that if this orange line is the correct length, it may allow for some limited windward sheeting of the traveler? But in that picture, the split in the core looks almost on the traveler cleat while that traveler is centered...

Windward traveler settings do prove beneficial on my F-boat in light to medium air using my conservative square-top. Yeah, I liked cats so much I got one with an extra hull