RRS 63.5(c)
If there is a conflict between
(1) two or more rules that must be resolved before a decision can be made, and
(2) those rules are in the notice of race, the sailing instructions, or any of the other documents that govern the event under item (g) of the definition Rule, then the protest committee shall apply the rule that it believes will provide the fairest result for all boats affected.
Q1) Once a PC determines what it "believes" and applies that belief in a decision, can the PC change its mind (continuing the construct) based upon new information or analysis?
Q2) If not, why not? If so, how and what is the correct procedure?
(1) ...
(2) it may have made a significant error, or
(3) significant new evidence has become available within a reasonable time.
The problem with using the "new evidence" here is that under what procedure is that evidence being presented and by whom? 63.5(c) says nothing about basing the PC's belief on evidence.
I don't really see an opportunity to go back and change the ruling just because the opinion has changed. That might be looked upon as favoring one party or another. There would always need to be some sort of new evidence or information (or an error corrected) in order to change a PC ruling IMO.
Yes, there is such a thing as an 'erroneous belief'.
But more to the point, regardless of the 'belief' relating to a fact or conclusion, it may be that the protest committee decides that there may have been a significant error in the outcome (decision).
A protest committee can always undo a wrong decision by reopening, even when RRS 90.3(e) is on: in that case the protest committee can publish it's correct decision, but the race committee cannot change the scores as a result.
A protest committee should always have enough spine to admit it may have been wrong, rather than looking for an excuse like ' new evidence '.