If green caused white to alter course before being on a close-hauled heading, then she has fouled white.  Room rights have not taken effect before the foul is committed.

I think you are correct. The rule number should be 18.3.
 rule wherr you tack in the zone. 
The a3 and a4 allen posters are different. 

Yours says the tacking boat is row, which is correct. 

Nothing says this boat broke a rule, but the rule to check is 18.3.

Looks like a rule 13 infringement. Not  18.3: If a boat passes head to wind.  In the drawing it passes head to wind before the zone. 

Green on port failed to keep clear of white on starboard, and broke RRS10.

Agree with Joep.

That diagram is based on the pre 2009 version of RRS 18.3, when the criterion for the tacking boat was 'completed her tack' in the zone.

Yes, it's 13 not 18.3 because Green passed head to wind before the zone..

Go ahead and send them edits.  I found some other errors, emailed them and they were very appreciative. Given that there are others, I'd imagine an updated version is in the works - Ang

Chin, note that pre 2009, when the criterion was 'completed the tack' in the zone, RRS 18.3 was designed only to begin to apply after RRS 13 ceased to apply, so the diagram is intended to show the tacking boat not breaking RRS 13 (and because the other boat is completely free to luff or bear away, the tacking boat does not break RRS 15 either).