Each of the 3 boats inside the pin wheel needed 10ft past the other boats bows to turn upwind, in effect that would be allowing minimum 10ft for 1st boat, then 10ft thereafter meaning 4th boat would be at least 40ft from mark to be close to legal and that is with 3 other boats doing it all perfect with disturbed wind for the second and third boats. The rules say you must allow for a seaman like manner so that is avoiding collision at all costs, you cannot just leave 1ft between boats in wind and waves, he is lucky the other boats chose to hit each other and not just sink the outside boat. A wiser skipper which hopefully he is now would slow down at the mark since he has approached from the perfect angle round up behind the inside boat with some speed and probably take a good apparent wind away from the mark on the perfect course instead of putting himself in such a poor position