From a rules perspective, (almost) none. The facts are what the protest committee finds them to be. That is why it is so important to present your case well at the hearing. An appeal can dispute a protest committee's application of the rules, but not the facts found. At best, you might be able to convice a PC to reopen a hearing, but unless significant new evidence comes to light, that is unlikely. I can tell you that finding the facts is the most difficult part of a protest hearing. It's rare that the parties agree on them. Two people can see the same event and honestly give two drastically different reports. PC has to sift through the testimony, reconstruct the incident, apply their knowledge of the physics of sailing, and determine what actually happened.

From a legal perspective, a lawsuit is a whole new can of worms. A court is not bound by a protest committee's findings, but is likely to give them weight.