Here is the situation...
Facts
Boat 1 (Blue) is a Laser on starboard tack sailing by the lee.
Boat 2 (Red) is a Laser on starboard tack in the same race who has already rounded the leeward mark and is sailing close-hauled.
Neither boat changes course.
The two boats make contact when the end of the boom of the Blue boat brushes the sail of the Red boat.
Applicable Definitions and Rules
Rule 11: ON THE SAME TACK, OVERLAPPED
When boats are on the same tack and overlapped, a windward boat shall keep clear of a leeward boat.
Tack, Starboard or Port A boat is on the tack, starboard or port, corresponding to her windward side.
Leeward and Windward A boat’s leeward side is the side that is or, when she is head to wind, was away from the wind. However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies. The other side is her windward side. When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat. The other is the windward boat.
OK. Here is why I am mystified by this one.
The Blue boat is sailing by the lee and so her leeward side is the side on which her mainsail lies, the port side. Therefore she is on starboard tack.
The Red boat's port side is her leeward side because it the side away from the wind. Therefore she is also on starboard tack.
(Note: the previous paragraph has been corrected from the first version of this post. In the original the fourth word of the first sentence was "starboard" which is clearly wrong. But it doesn't affect the sense of the rest of the post.)
Clearly the boats are overlapped so Rule 11 applies.
But which boat is windward and which is leeward?
Both boats could claim that they were the leeward boat because contact was made with the the leeward side of the other boat. On the other hand both boats would also have to concede that the other boat is on their own leeward side.
So have both boats infringed Rule 11? Or neither? Or if only one has, why?
This situation is a bit similar to the one posed by Jos Spijkerman on his blog, Who Has to Keep Clear? My example may also be the answer to the question posed by John Doerr in Scuttlebutt Newsletter 2733 last week, "Of interest to some will be the situation where both boats are leeward and on starboard. Now neither of them has any obligation to keep clear (but they must avoid contact). Can you construct that situation?"
Update: In the example above the two boats make contact with their leeward sides. A similar situation could be imagined where it is the windward sides of both boats that make contact. See Bigger Crunch. Same issue. Both boats could legitimately claim that they were the leeward boat and protest the other under Rule 11. Is the other example fundamentally different in any way?