Some clarifications:
[*]L establishes an overlap to leeward of W from clear astern, I presume within two of her boatlengths.
Questionable. I don't think L was further away than 2 boat lengths from W initially, but barely. The hole between the two was big. When I "barged in" the hole was big enough for me, with room to head up without impairing upon W and the same amount below separating me from L. You could fit a laser on each side, with room to spare.
The line also had a strong bias, left was definitely favored, aka being head to wind you were at an angle with the line, so much so that a 49er was able to port tack the whole fleet (and not capsize doing so for once

There are some points in the story that make me suspect that the boats were too close. For example, When L turned down, and her transom swung over, how could M keep clear by heading up? Wouldn't that cause M's transom to swing towards L, making matters worse? Or was she only overlapped bow-to-stern? Also, when M made contact with W, W was head-to-wind, but M was not. How is that possible unless M and W were barely overlapped as well? I have difficulty reconciling that small an overlap on both sides, with having a large hole to sail into.
I was further back, W and L were both in front of me. I had an overlap on both, only bow to stern on W but almost side by side with L. Before L started to luff me I was trying hard to stop the boat from creeping forward as I felt I was too close to the line. When L started to luff me it also picked up speed and moved forward more but not enough for me to bear away and duck behind it, my spi pole would have hit for sure and my starboard hull as well probably. When L bore away its stern passed in front of my port bow and under my spi pole but was still a good meter away from W. When I headed up and hit W sideways, my starboard bow was at the level of his shrouds.
Right after the touch I was able to bear away behind the FF transom.
Maybe of importance, and that I learned only after, L and W were both fighting for the series first place, pushing W over the line was of outmost importance for L and allowed him to win the series by one point...
But I agree, I have a knack to put myself in impossible situations, maybe I should be penalized for it.