The use of arbitration was posted in the NOR. The actual procedure was to be posted as an addendum to the SIs, though, and is therefore apparently not available online.
The usual arbitration procedure is that if the parties involved are not satisfied with the concensus of the arbitration (not necessarily the decision, but more the interpretations and outside viewpoint) they can go to a formal protest. However, if they are satisfied that a jury of their peers all see the incident in a certain way, then going to a protest will almost certainly result in a similar verdict (and therefore a waste of everyone's time). What I'm not sure of is if holding an arbitration meeting can be done without filing a protest; is the protest withdrawn if it stops at arbritation; does this then count against any US Sailing report re the RC? Some bean counting type issues there.
We are missing all the information presented at the hearing, so we have NO way of knowing why the offending boat was DSQ, and why the affected boat was not given redress. My GUESS is that the hearing revealed that the offending skipper was proven to have recognised the foul, and did not volunteer a penalty turn. Could he have overturned this in a formal hearing? Maybe, but maybe he didn't want to further compound his initial failure to accept fault. Don't know why he wouldn't have RAF'd himself then (retired after finishing) vs accepting a DSQ, though. No idea on why no redress, unless having your tiller knocked out of your hand is no excuse for then hitting the mark and having to do a turn (in traffic). Maybe he was yelling too much and not grabbing the tiller enough :-) Total conjecture on my part.
I have no problems with arbitration hearings; maybe they prevent some of the BS protests. They can easily stop a lot of newbie protests between people ignorant of or mixed up on rules. Probably less effective for serious complex issues. If nothing else, they involve a bigger circle of people who can now tell other sailors "we told Joe Sea Lawyer that his protest didn't hold water, but he went ahead anyway". In the end, a bad reputation is the only penalty for too many protests.