Not sure what just happened exactly

I had just finished putting my whoopie ridgeline on my new DIY DL hammock. (just like with my HH I made it too long even at the shortest adjustment...great)
I go to sit down for the first time and almost immediately hear a snap and drop from a sitting position onto the ground with a thud.

Glad I wasn't showing it to friends.

A was looking to the side that failed but only saw the lines zipping through the air for a split second. I thought maybe somehow it was the whoopie on that side that broke but it looks fine.

The toggle on that end is a half inch thick carbon tube. It collapsed in on itself so rather than an O it now looks more like ()() but it was still in place in the marlin spike hitch afterwards. The knot had not tightened down around the new smaller collapsed diameter.

What doesn't make sense to me though is even if the marlin spike knot tightened down so hard on the tube (doubt it) to collapse it, the whoopie wouldn't have slipped off without bending the split tube at the knot.

The only thing I can think is that the whoopie got loose while I was untwisting the hammock and snagged the edge of the toggle as it came down and crushed it as the loop impacted it and then slipped off to the side in one smooth motion.

Not sure how I feel about these toggles now.