Tony, I'm not buying that.

B keeps clear and two gybes later she hits the mark.

That was a result of B rushing her gybes and misjudging her approach to the mark.

But as a tactical assessment I wouldn't expect B to even try to luff in front of Y.

As diagrammed, it's all on Y.  I think the only option for Y is to change course to starboard and let B through.

I, too, have heard that there's a case on the way.  I believe that it's silly to "interpret" False as True, which was what they'd be doing. It tortures the meaning of "interpret" beyond reason (IMHO).

John A .. ok .. let me try to understand the hand/foot argument. 

Take that crew holding the boat and standing on the bottom. They bend their legs at the knees and are now hanging-still holding onto the toe-rail. Is that person now breaking 42?  (How is a swimmer to return to the boat?)

If not, why?  
If so, are we then saying you can put your entire body in the water .. but not your hand?  Can't crew sit on the rail and have their feet touch the water?

Phil, How do you conclude that W was not required to act to avoid contact until it became clear that L was not keeping clear?

L was the right of way boat.  She was not  required to keep clear.

W was not entitled to room.

Niko: I like your "the RC should always work to have an appropriate level of management commensurate with the competition level/importance" comment.

There is one event that may partner and I run every year ... the Warneet Around French Island race. While Monica runs the briefing giving numerous examples of the flags used during the start sequence there is usually an America's Cup skipper sitting quietly and respectfully at the back of the room with his family or mates. At the other end of the spectrum we have some who have NEVER raced before or perhaps doing their second race since last year.

During this race I tend to be very chatty on the radio to be sure that even those with the least experience have a great day on the water.

One boat in his first year actually missed the starting line, but we considered him a starter. The next year his missed the finishing line but we gave him a finish regardless. He was so pleased that he got the start right the second year ;-)

That said, it is quite a different matter if I am running a one-design race.