Why would Blue's leeward rights be eliminated because of a windward port boat that was in a bad place? Blue was clear astern of green and sailing proper course. Yellow must slow down or tack to avoid the two other boats with rights in this situation. If I were blue and had to alter course to avoid a collision with yellow I would protest and expect a penalty turn on the water. If they didn't comply I guess I'd learn from the protest committee why I was wrong (I'm 0 for 1 in that setting).
Hmm ? interesting... Well green definitely has nothing to worry about. Yellow has to duck green, I think blue has to fall off as well in order to avoid collision... I wouldn't think blue has any rights in this particular situation... I mean what would you expect yellow to do... UNLESS yellow was able to fall behind blue but as you state in this scenario that's pretty much impossible if they are over lapped... While the situation sucks, I don't think blue would win a protest