"Do the Right Thing...It's Just Business"

As a freelancer, I do a lot of business with different clients. Usually we contract for a certain rate (only in rare cases does that actually involve a real contract), I do the work and they (eventually) pay. Ideal would be immediate payment on delivery of the product, which is submitted by a certain deadline adhered to by both parties. But realistically, there's often a delay on the return. And sometimes, an initial client meeting clarifies that there's no chemistry between us and we go our separate ways. That's business. With that as preamble, allow me to introduce the following situation (already well-covered in the blogosphere during my Middle East assignment, most notably here, in a post cited by the ever topical Steve Silver). A man and a woman meet on JDate (or any other online site). They trade an email or two, talk once or twice and decide to go out. They go to an expensive dinner (his choice); when the bill comes she offers to pay half, and he tells her he'll take care of it. They both go to their respective homes; when he calls her a few days later, she doesn't call him back. And that's where it all goes to hell. He gets it in his head that she owes him her half of the dinner bill and that he aims to collect it. He sends her emails and leaves her a series of voice mail messages to that effect, first appealing to her to "do the right thing"--since dating is equal to business in his world, her agreeing to accept his offer of dinner payment was her unspoken acceptance that there would be a future date--and ultimately threatening legal action against her at her place of business. The guy has a strong confident voice, and conveys that he's used to doing business. Even while threatening, he seems socially able, if annoying--as if he's reporting on traffic conditions or conveying information about an apartment she might be interested in, telling her that "the ball's totally in her court" and that she should "do the right thing." Soon the voice mails and emails are all over the internet, including his name and hers, and being discussed all over the blogosphere. But it's fifty bucks. Let me repeat that. Fifty bucks. While fifty bucks is nothing that's ever been spent on me for a first date, and perhaps it shouldn't be, it's still not a major amount of money for anyone with an actual job. For him, I doubt it's about the money. It's a control issue; it's a rejection issue; and it's the principle of the thing--he wanted to go out with her, and she didn't, therefore he feels that she owes him. But that doesn't mean she owes him money, whether it's fifty or two hundred and fifty bucks. But this situation raises questions about what's right from a point of etiquette, from a point of technical legality, and from a point of menschlikhkeit (behaving like a mensch). There's no way to know if "let's split it" means "let's split it," or "let's never do this again." I understand the pain of not being called back. And, although not proudly, I will admit to not having called guys back even if I said I would; when a guy asks if he can call again, it's harder to say "I don't think so" than it is to say "sure." Is agreeing to go on a date a business transaction? If so, is there any standard contract, terms to which both parties have implicitly agreed even though no one signed anything? How does one dissolve a partnership that was never started? And what are our obligations to the men and women we date?