FWIW, I agree with parts of what both of you are saying. "Reasonable" without the video is going to be almost impossible. Even with the video, it might be hard for some juries to get there. It was a fast incident, near a mark that starboard boats normally round and turn downwind. I know that P doesn't have to anticipate S's course change, but it is a very basic part of the game to round that mark in the manner that they did. No excuse at all for S not watching for traffic, however.

Separate from 10 and 14, here's something I would also discuss during a hearing: As I noted above, S was changing course throughout, both in rounding the mark and the "deer" wiggle. P could make a compelling case that under 16.1, S should be DSQ.

Mike