or "The difference between what is said and what is written" *
During a protest hearing everything a witness tells or shows is evidence. What the parties say and show and draw is evidence. If both parties agree that they were on port tack that is still only evidence, not a fact. If one of them brings a broken tiller extension, that extension would be evidence. Every drawing or description or placed model on the table, still is only evidence. The opinion of another official, say a measurer, is evidence, so is a video or a photograph. Some evidence may be of little or no value, for instance if it's hearsay evidence and the original person who said it, isn't available for questioning. Or a written statement, which can be introduced if parties agree, again without the person who wrote it, may be of limited value. All is evidence!
Only the protest committee can find facts. Based on the evidence, usually in private and only after a valid protest hearing. If the protest committee decides the tiller extension is broken or both parties were on port tack, it becomes a fact. Even if that fact has not actually happened or isn't true. If the PC agree on it, it becomes a fact. The drawing endorsed or drawn by the committee becomes fact.
And facts cannot be appealed!
It is therefore important to give the evidence that will lead the committee to find what you consider to be facts, which reflect what you think actually happened. Don't try to guide them in applying the appropriate rule. Make sure they find the correct facts.
The committee will draw a conclusion on the facts found. If they draw a - in your eyes - wrong conclusion you have a case to appeal. But the appeals committee cannot change facts found, only the conclusion. If the facts are unreasonable or not consistent, the appeals committee might return the protest for reconsideration or appoint a new committee to start all over again. The latter happens more often, when the procedure hasn't been followed correctly.
There's no burden of proof or something like "beyond a reasonable doubt". Only weighing of the evidence. If your opponent is a gorgeous intelligent blond, you might have a slight disadvantage... deal with it. The rule book allows no other way.
Scientia potentia est
* source: PROTEST & APPEALS by Brian Willis, 1995