Sometimes when the gulf in communication is so wide I'm not sure where to start. So forgive me if it sounds like I'm talking down to you, but I can't figure out where the disconnect is.
1) Yes, anonymous people can post anything on the internet. Sometimes what they post is true. The majority of the posts on this board, true or false, are not verifiable with a reasonable degree of certainty by the members of this board. The question then becomes how to respond to an unverifiable accusation.
2) One important consideration, of course, is the likelihood that the accusation is true. In assessing this, it is reasonable to inquire whether there is any independent corroborating evidence, but it is a fallacy to assume that such evidence must exist, and infer evidence of absence from the absence of evidence. It is rare to have extrinsic evidence of sexual misconduct that falls short of forcible stranger rape. And it is depressingly common for members of the general public to apply a degree of scrutiny to these claims that they don't use for other types of equally unsubstantiated allegations. (I notice you don't make much of the dive shop's failure to respond for example. Shouldn't the innocent proclaim their innocence whenever they have the chance? Doesn't it mean something if they don't?)
3) An additional consideration in evaluating credibility is motive to fabricate, both on the part of the accuser and on the part of those who corroborate or contradict the accuser. It's amazing how many reasons those who inherently distrust women can think up for those women to lie, yet fail to apply the same stringent evidentiary standards to their own reasoning (i.e. where's your evidence that women fabricate sexual misconduct allegations for revenge over minor disputes? Does it even make sense to do so given how women are raked over the coals for speaking up about this?) And when someone who appears to be speaking in defense of the accused confirms some details of the accuser's story, why is it not clear that those parts, at least, are true? Why do you continue to entertain such theories as this story was made up out of whole cloth by a competing dive shop? And why aren't you equally skeptical of the denials of the accused as you are of the accusers? Surely those who sexually harass young women have a strong motive to lie about it.
4) Which brings us to the final consideration: cost of being wrong in either direction. In any scenario in which you are presented with unsubstantiated allegations, you have to decide what you're going to do with that information without necessarily being able to immediately confirm or disprove them. You could dismiss them out of hand, as you've done here (but have you done it with any of the other unsubstantiated stories told here? If not, why not?) You could believe everything you read, which no one is advocating for. Or you could engage your critical thinking skills. You could recognize that women rarely lie about these things and are far more often disbelieved when telling the truth. You could consider that loudly proclaiming your disbelief intimidates other victims into keeping silent and allows these abuses to continue. You could meditate on the fact that it really doesn't cost you much to shut up and keep an open mind while the story develops. And you could ask yourself questions like "who has more to gain here, and more to lose?" And you could reach at least a tentative hunch in favor of believing victims based on a more sophisticated thought process than putting your fingers in your ears and saying la-la-la you have no proof so you must be lying.
