Earlier I said this: "Whether or not a protest is determined to be valid can be based on a number of things, including procedures for notification, etc."
I stand by this statement, as it can be true, sometimes PCs (and OAs) act strangely. In addition, there are still lots of events that ADD protest requirements (notify RC at the end of a race, etc.), raising the bar even higher for protest validity.
However, as Eric and Matt pointed out, there are plenty of provisions in the RRS to allow (require) PCs to hear and decide protests, even if some validity requirements are not met. In my opinion, and many others here agree, this is very important, we need to get away from the old days when the first thing a PC did was sit down and find a reason to chuck the protest altogether. I see this happening less and less at the events I attend, so it's definitely a good trend.
In any event, lots of good posts here. In the case of the original post of this thread, the victim probably has a good court case against not only the offending sailor, but potentially against the OA. Especially here in the lawyer-intense US...
Mike