Ok all you rules junkies....here's one for you...

First the setting:
Winds 15-20
boats Nacra 20s (could really be any high performance spin boat)

OK....

S has rounded the windward mark, hoisted their spinaker and is headed downwind on starboard.

P is coming into the windward mark on Port and is close hauled.

S & P are on a direct collision course with about 100 to 150 yards between them. P knows he has to avoid S, and cannot go above S because he is already close hauled, so he starts to sheet out and bear off to go below. Just as P begins to bear off, S is hit with a puff and also bears off. (assume S is NOT hunting...at least not intentionally) P now sees S bearing off, and so quickly changes to go above, sheets in and pushes the stick. Puff is gone and S now comes back up forcing P to once again change and bear off quickly to avoid collision and go below at the last second. S also had to blow their spin to go higher to avoid the collision and protests P for causing him to alter course.

Now....It is my opinion that although ROW boat has an obligation to hold their course once the give way boat has altered to avoid, given the performance characteristics and conditions here, S was probably in his rights to bear away to avoid capsizing and therefor P had to alter course from their original intent. HOWEVER....am I wrong to assume that once S bore away, they should no longer be within their rights to come back up, thereby forcing P to alter for avaoidance yet again???? Or....(as S insists) is he perfectly within his rights to alter course up and down as part of his "normal course"???