Mike,
I am failing to see, even with a 5-length zone, that black was overlapped inside of red.
Mike
The rounding is to starboard on the left hand mark of a gate. Red and black were overlapped from the time red jibed on to starboard (way, way back).
This situation happens in catamarans all the time - except for the skewering part.
Otherwise, I'm inclined to agree that black did not break RRS 10 - red was going to jibe there anyway. They just misjudged the distance between their prod and the UP boat. DSQ Red - RRS 16.1 and 14. UP entitled to redress (assuming injury) - RRS 62.1(b )