Beau ... here is maybe how I'd look it.

Let's say for the sake of argument that a boat doing 1/2 of a roll tack from a standstill is going to be hard to enforce.  So .. let's say 1/2 roll tack that is part of a boat's "start" is going to be not called. So what are the components of that?

So, when does one call it?  When those elements are not present. 

Given your distinction between "avoid" and "pass", how would that factor in if you took almost the same scenario, but yellow was moving slowly, or almost stationary, and blue "ended up" quickly passing yellow.   How would all involved be able to actually make that determination (of whether they would pass or not) when they are at the decision point.  I think the answer is "you can't".  

I do find it curious the interpretation of "may" that might imply a 3rd option of "not choosing".   To me it still seems like the importance is on the choice of sides and not the distinction between "pass" and "avoid" or the exact interpretation of "pass".  You can clearly and in advance, choose the side you want the obstruction to pass you on, but it is harder to determine if it will actually result in "passing".

What if the rule read: " ... boat may choose to pass or avoid an obstruction on her ...".

Chris

"If the details included remove any ambiguity about which incident the delivered protest is referring to"
Clear as mud.
Does not answer the question.

Ben,
Safety is rule 1 and 14 obligates boats to avoid contact or not to cause contact. There was reasonable apprehension in the mind of ROW boat that there may be a collision and she took action to avoid that situation. In my opinion, I will DSQ KC boat.

Yes we've used W finishes for many fleet events.  It works well for the back of the fleet. Not entirely sure the front of the fleet would be thrilled at having it used if they weren't 100% sure they were being recorded at the front.

I realise handicap racing is not popular on this board. For reference - W finishes are not appropriate in handicap races as you need to adjust time and 'distance' (laps).