Left Lay, Right Lay?

I apologize for my lack of knowledge on terms, but I'll give this a try: From the top, a halyard has a free spinning "bullet" to which the swage eye of the luff line attaches, and the luff line is sewn into the luff of the sail, and is seized at each end into a triangle attached to the swage. The bottom swage is attached to the light roller furler, with one furling line to furl (sheet is pulled with furling line uncleated and freed to unfurl the sail). I burst of wind apparently was the source of the failure, either by whipping the furled sail until the wire failed, or perhaps unravelling the sail a few feet and then twisting the wire to breaking point.

I've had a time getting my mind around this, so I built a little model to find that all the forces would have "tightened" the lay in my configuration (left lay).

I've got maybe a better question: what does a failed luff wire look like when it's "birdcage" failed compared to "overtightened" failure?